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2023-10-31Merge tag 'x86-core-2023-10-29-v2' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 core updates from Thomas Gleixner: - Limit the hardcoded topology quirk for Hygon CPUs to those which have a model ID less than 4. The newer models have the topology CPUID leaf 0xB correctly implemented and are not affected. - Make SMT control more robust against enumeration failures SMT control was added to allow controlling SMT at boottime or runtime. The primary purpose was to provide a simple mechanism to disable SMT in the light of speculation attack vectors. It turned out that the code is sensible to enumeration failures and worked only by chance for XEN/PV. XEN/PV has no real APIC enumeration which means the primary thread mask is not set up correctly. By chance a XEN/PV boot ends up with smp_num_siblings == 2, which makes the hotplug control stay at its default value "enabled". So the mask is never evaluated. The ongoing rework of the topology evaluation caused XEN/PV to end up with smp_num_siblings == 1, which sets the SMT control to "not supported" and the empty primary thread mask causes the hotplug core to deny the bringup of the APS. Make the decision logic more robust and take 'not supported' and 'not implemented' into account for the decision whether a CPU should be booted or not. - Fake primary thread mask for XEN/PV Pretend that all XEN/PV vCPUs are primary threads, which makes the usage of the primary thread mask valid on XEN/PV. That is consistent with because all of the topology information on XEN/PV is fake or even non-existent. - Encapsulate topology information in cpuinfo_x86 Move the randomly scattered topology data into a separate data structure for readability and as a preparatory step for the topology evaluation overhaul. - Consolidate APIC ID data type to u32 It's fixed width hardware data and not randomly u16, int, unsigned long or whatever developers decided to use. - Cure the abuse of cpuinfo for persisting logical IDs. Per CPU cpuinfo is used to persist the logical package and die IDs. That's really not the right place simply because cpuinfo is subject to be reinitialized when a CPU goes through an offline/online cycle. Use separate per CPU data for the persisting to enable the further topology management rework. It will be removed once the new topology management is in place. - Provide a debug interface for inspecting topology information Useful in general and extremly helpful for validating the topology management rework in terms of correctness or "bug" compatibility. * tag 'x86-core-2023-10-29-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) x86/apic, x86/hyperv: Use u32 in hv_snp_boot_ap() too x86/cpu: Provide debug interface x86/cpu/topology: Cure the abuse of cpuinfo for persisting logical ids x86/apic: Use u32 for wakeup_secondary_cpu[_64]() x86/apic: Use u32 for [gs]et_apic_id() x86/apic: Use u32 for phys_pkg_id() x86/apic: Use u32 for cpu_present_to_apicid() x86/apic: Use u32 for check_apicid_used() x86/apic: Use u32 for APIC IDs in global data x86/apic: Use BAD_APICID consistently x86/cpu: Move cpu_l[l2]c_id into topology info x86/cpu: Move logical package and die IDs into topology info x86/cpu: Remove pointless evaluation of x86_coreid_bits x86/cpu: Move cu_id into topology info x86/cpu: Move cpu_core_id into topology info hwmon: (fam15h_power) Use topology_core_id() scsi: lpfc: Use topology_core_id() x86/cpu: Move cpu_die_id into topology info x86/cpu: Move phys_proc_id into topology info x86/cpu: Encapsulate topology information in cpuinfo_x86 ...
2023-10-13x86/apic, x86/hyperv: Use u32 in hv_snp_boot_ap() tooIngo Molnar1-2/+2
The data type for APIC IDs was standardized to 'u32' in the following recent commit: db4a4086a223 ("x86/apic: Use u32 for wakeup_secondary_cpu[_64]()") Which changed the function arguments type signature of the apic->wakeup_secondary_cpu() APIC driver function. Propagate this to hv_snp_boot_ap() as well, which also addresses a 'assignment from incompatible pointer type' build warning that triggers under the -Werror=incompatible-pointer-types GCC warning. Fixes: db4a4086a223 ("x86/apic: Use u32 for wakeup_secondary_cpu[_64]()") Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20230814085113.233274223@linutronix.de
2023-09-22x86/hyperv: Remove hv_vtl_early_init initcallSaurabh Sengar1-0/+2
There has been cases reported where HYPERV_VTL_MODE is enabled by mistake, on a non Hyper-V platforms. This causes the hv_vtl_early_init function to be called in an non Hyper-V/VTL platforms which results the memory corruption. Remove the early_initcall for hv_vtl_early_init and call it at the end of hyperv_init to make sure it is never called in a non Hyper-V platform by mistake. Reported-by: Mathias Krause <minipli@grsecurity.net> Closes: https://lore.kernel.org/lkml/40467722-f4ab-19a5-4989-308225b1f9f0@grsecurity.net/ Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com> Acked-by: Mathias Krause <minipli@grsecurity.net> Signed-off-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/1695358720-27681-1-git-send-email-ssengar@linux.microsoft.com
2023-09-04Merge tag 'hyperv-next-signed-20230902' of ↵Linus Torvalds1-9/+62
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv updates from Wei Liu: - Support for SEV-SNP guests on Hyper-V (Tianyu Lan) - Support for TDX guests on Hyper-V (Dexuan Cui) - Use SBRM API in Hyper-V balloon driver (Mitchell Levy) - Avoid dereferencing ACPI root object handle in VMBus driver (Maciej Szmigiero) - A few misecllaneous fixes (Jiapeng Chong, Nathan Chancellor, Saurabh Sengar) * tag 'hyperv-next-signed-20230902' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (24 commits) x86/hyperv: Remove duplicate include x86/hyperv: Move the code in ivm.c around to avoid unnecessary ifdef's x86/hyperv: Remove hv_isolation_type_en_snp x86/hyperv: Use TDX GHCI to access some MSRs in a TDX VM with the paravisor Drivers: hv: vmbus: Bring the post_msg_page back for TDX VMs with the paravisor x86/hyperv: Introduce a global variable hyperv_paravisor_present Drivers: hv: vmbus: Support >64 VPs for a fully enlightened TDX/SNP VM x86/hyperv: Fix serial console interrupts for fully enlightened TDX guests Drivers: hv: vmbus: Support fully enlightened TDX guests x86/hyperv: Support hypercalls for fully enlightened TDX guests x86/hyperv: Add hv_isolation_type_tdx() to detect TDX guests x86/hyperv: Fix undefined reference to isolation_type_en_snp without CONFIG_HYPERV x86/hyperv: Add missing 'inline' to hv_snp_boot_ap() stub hv: hyperv.h: Replace one-element array with flexible-array member Drivers: hv: vmbus: Don't dereference ACPI root object handle x86/hyperv: Add hyperv-specific handling for VMMCALL under SEV-ES x86/hyperv: Add smp support for SEV-SNP guest clocksource: hyper-v: Mark hyperv tsc page unencrypted in sev-snp enlightened guest x86/hyperv: Use vmmcall to implement Hyper-V hypercall in sev-snp enlightened guest drivers: hv: Mark percpu hvcall input arg page unencrypted in SEV-SNP enlightened guest ...
2023-08-25x86/hyperv: Remove hv_isolation_type_en_snpDexuan Cui1-7/+4
In ms_hyperv_init_platform(), do not distinguish between a SNP VM with the paravisor and a SNP VM without the paravisor. Replace hv_isolation_type_en_snp() with !ms_hyperv.paravisor_present && hv_isolation_type_snp(). The hv_isolation_type_en_snp() in drivers/hv/hv.c and drivers/hv/hv_common.c can be changed to hv_isolation_type_snp() since we know !ms_hyperv.paravisor_present is true there. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20230824080712.30327-10-decui@microsoft.com
2023-08-25x86/hyperv: Use TDX GHCI to access some MSRs in a TDX VM with the paravisorDexuan Cui1-4/+4
When the paravisor is present, a SNP VM must use GHCB to access some special MSRs, including HV_X64_MSR_GUEST_OS_ID and some SynIC MSRs. Similarly, when the paravisor is present, a TDX VM must use TDX GHCI to access the same MSRs. Implement hv_tdx_msr_write() and hv_tdx_msr_read(), and use the helper functions hv_ivm_msr_read() and hv_ivm_msr_write() to access the MSRs in a unified way for SNP/TDX VMs with the paravisor. Do not export hv_tdx_msr_write() and hv_tdx_msr_read(), because we never really used hv_ghcb_msr_write() and hv_ghcb_msr_read() in any module. Update arch/x86/include/asm/mshyperv.h so that the kernel can still build if CONFIG_AMD_MEM_ENCRYPT or CONFIG_INTEL_TDX_GUEST is not set, or neither is set. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20230824080712.30327-9-decui@microsoft.com
2023-08-25x86/hyperv: Introduce a global variable hyperv_paravisor_presentDexuan Cui1-5/+10
The new variable hyperv_paravisor_present is set only when the VM is a SNP/TDX VM with the paravisor running: see ms_hyperv_init_platform(). We introduce hyperv_paravisor_present because we can not use ms_hyperv.paravisor_present in arch/x86/include/asm/mshyperv.h: struct ms_hyperv_info is defined in include/asm-generic/mshyperv.h, which is included at the end of arch/x86/include/asm/mshyperv.h, but at the beginning of arch/x86/include/asm/mshyperv.h, we would already need to use struct ms_hyperv_info in hv_do_hypercall(). We use hyperv_paravisor_present only in include/asm-generic/mshyperv.h, and use ms_hyperv.paravisor_present elsewhere. In the future, we'll introduce a hypercall function structure for different VM types, and at boot time, the right function pointers would be written into the structure so that runtime testing of TDX vs. SNP vs. normal will be avoided and hyperv_paravisor_present will no longer be needed. Call hv_vtom_init() when it's a VBS VM or when ms_hyperv.paravisor_present is true, i.e. the VM is a SNP VM or TDX VM with the paravisor. Enhance hv_vtom_init() for a TDX VM with the paravisor. In hv_common_cpu_init(), don't decrypt the hyperv_pcpu_input_arg for a TDX VM with the paravisor, just like we don't decrypt the page for a SNP VM with the paravisor. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20230824080712.30327-7-decui@microsoft.com
2023-08-25x86/hyperv: Support hypercalls for fully enlightened TDX guestsDexuan Cui1-0/+14
A fully enlightened TDX guest on Hyper-V (i.e. without the paravisor) only uses the GHCI call rather than hv_hypercall_pg. Do not initialize hypercall_pg for such a guest. In hv_common_cpu_init(), the hyperv_pcpu_input_arg page needs to be decrypted in such a guest. Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20230824080712.30327-3-decui@microsoft.com
2023-08-25x86/hyperv: Add hv_isolation_type_tdx() to detect TDX guestsDexuan Cui1-0/+3
No logic change to SNP/VBS guests. hv_isolation_type_tdx() will be used to instruct a TDX guest on Hyper-V to do some TDX-specific operations, e.g. for a fully enlightened TDX guest (i.e. without the paravisor), hv_do_hypercall() should use __tdx_hypercall() and such a guest on Hyper-V should handle the Hyper-V Event/Message/Monitor pages specially. Reviewed-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Tianyu Lan <tiala@microsoft.com> Signed-off-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20230824080712.30327-2-decui@microsoft.com
2023-08-23x86/hyperv: Add missing 'inline' to hv_snp_boot_ap() stubNathan Chancellor1-1/+1
When building without CONFIG_AMD_MEM_ENCRYPT, there are several repeated instances of -Wunused-function due to missing 'inline' on the stub of hy_snp_boot_ap(): In file included from drivers/hv/hv_common.c:29: ./arch/x86/include/asm/mshyperv.h:272:12: error: 'hv_snp_boot_ap' defined but not used [-Werror=unused-function] 272 | static int hv_snp_boot_ap(int cpu, unsigned long start_ip) { return 0; } | ^~~~~~~~~~~~~~ cc1: all warnings being treated as errors Add 'inline' to fix the warnings. Fixes: 44676bb9d566 ("x86/hyperv: Add smp support for SEV-SNP guest") Signed-off-by: Nathan Chancellor <nathan@kernel.org> Reviewed-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20230822-hv_snp_boot_ap-missing-inline-v1-1-e712dcb2da0f@kernel.org
2023-08-22x86/hyperv: Add smp support for SEV-SNP guestTianyu Lan1-0/+8
In the AMD SEV-SNP guest, AP needs to be started up via sev es save area and Hyper-V requires to call HVCALL_START_VP hypercall to pass the gpa of sev es save area with AP's vp index and VTL(Virtual trust level) parameters. Override wakeup_secondary_cpu_64 callback with hv_snp_boot_ap. Reviewed-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <tiala@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20230818102919.1318039-8-ltykernel@gmail.com
2023-08-22x86/hyperv: Use vmmcall to implement Hyper-V hypercall in sev-snp ↵Tianyu Lan1-3/+27
enlightened guest In sev-snp enlightened guest, Hyper-V hypercall needs to use vmmcall to trigger vmexit and notify hypervisor to handle hypercall request. Signed-off-by: Tianyu Lan <tiala@microsoft.com> Reviewed-by: Dexuan Cui <decui@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20230818102919.1318039-6-ltykernel@gmail.com
2023-08-22x86/hyperv: Add sev-snp enlightened guest static keyTianyu Lan1-0/+2
Introduce static key isolation_type_en_snp for enlightened sev-snp guest check. Reviewed-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <tiala@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Link: https://lore.kernel.org/r/20230818102919.1318039-2-ltykernel@gmail.com
2023-08-05Merge tag 'hyperv-fixes-signed-20230804' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv fixes from Wei Liu: - Fix a bug in a python script for Hyper-V (Ani Sinha) - Workaround a bug in Hyper-V when IBT is enabled (Michael Kelley) - Fix an issue parsing MP table when Linux runs in VTL2 (Saurabh Sengar) - Several cleanup patches (Nischala Yelchuri, Kameron Carr, YueHaibing, ZhiHu) * tag 'hyperv-fixes-signed-20230804' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: Drivers: hv: vmbus: Remove unused extern declaration vmbus_ontimer() x86/hyperv: add noop functions to x86_init mpparse functions vmbus_testing: fix wrong python syntax for integer value comparison x86/hyperv: fix a warning in mshyperv.h x86/hyperv: Disable IBT when hypercall page lacks ENDBR instruction x86/hyperv: Improve code for referencing hyperv_pcpu_input_arg Drivers: hv: Change hv_free_hyperv_page() to take void * argument
2023-07-24x86/hyperv: fix a warning in mshyperv.hZhiHu1-1/+1
The following checkpatch warning is removed: WARNING: Use #include <linux/io.h> instead of <asm/io.h> Signed-off-by: ZhiHu <huzhi001@208suo.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org>
2023-06-05clocksource: hyper-v: Provide noinstr sched_clock()Peter Zijlstra1-0/+5
With the intent to provide local_clock_noinstr(), a variant of local_clock() that's safe to be called from noinstr code (with the assumption that any such code will already be non-preemptible), prepare for things by making the Hyper-V TSC and MSR sched_clock implementations noinstr. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Co-developed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Michael Kelley <mikelley@microsoft.com> # Hyper-V Link: https://lore.kernel.org/r/20230519102715.843039089@infradead.org
2023-04-29Merge tag 'objtool-core-2023-04-27' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull objtool updates from Ingo Molnar: - Mark arch_cpu_idle_dead() __noreturn, make all architectures & drivers that did this inconsistently follow this new, common convention, and fix all the fallout that objtool can now detect statically - Fix/improve the ORC unwinder becoming unreliable due to UNWIND_HINT_EMPTY ambiguity, split it into UNWIND_HINT_END_OF_STACK and UNWIND_HINT_UNDEFINED to resolve it - Fix noinstr violations in the KCSAN code and the lkdtm/stackleak code - Generate ORC data for __pfx code - Add more __noreturn annotations to various kernel startup/shutdown and panic functions - Misc improvements & fixes * tag 'objtool-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits) x86/hyperv: Mark hv_ghcb_terminate() as noreturn scsi: message: fusion: Mark mpt_halt_firmware() __noreturn x86/cpu: Mark {hlt,resume}_play_dead() __noreturn btrfs: Mark btrfs_assertfail() __noreturn objtool: Include weak functions in global_noreturns check cpu: Mark nmi_panic_self_stop() __noreturn cpu: Mark panic_smp_self_stop() __noreturn arm64/cpu: Mark cpu_park_loop() and friends __noreturn x86/head: Mark *_start_kernel() __noreturn init: Mark start_kernel() __noreturn init: Mark [arch_call_]rest_init() __noreturn objtool: Generate ORC data for __pfx code x86/linkage: Fix padding for typed functions objtool: Separate prefix code from stack validation code objtool: Remove superfluous dead_end_function() check objtool: Add symbol iteration helpers objtool: Add WARN_INSN() scripts/objdump-func: Support multiple functions context_tracking: Fix KCSAN noinstr violation objtool: Add stackleak instrumentation to uaccess safe list ...
2023-04-18x86/hyperv: VTL support for Hyper-VSaurabh Sengar1-0/+10
Virtual Trust Levels (VTL) helps enable Hyper-V Virtual Secure Mode (VSM) feature. VSM is a set of hypervisor capabilities and enlightenments offered to host and guest partitions which enable the creation and management of new security boundaries within operating system software. VSM achieves and maintains isolation through VTLs. Add early initialization for Virtual Trust Levels (VTL). This includes initializing the x86 platform for VTL and enabling boot support for secondary CPUs to start in targeted VTL context. For now, only enable the code for targeted VTL level as 2. When starting an AP at a VTL other than VTL0, the AP must start directly in 64-bit mode, bypassing the usual 16-bit -> 32-bit -> 64-bit mode transition sequence that occurs after waking up an AP with SIPI whose vector points to the 16-bit AP startup trampoline code. Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Stanislav Kinsburskii <stanislav.kinsburskii@gmail.com> Link: https://lore.kernel.org/r/1681192532-15460-6-git-send-email-ssengar@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2023-04-18x86/hyperv: Make hv_get_nmi_reason publicSaurabh Sengar1-0/+5
Move hv_get_nmi_reason to .h file so it can be used in other modules as well. Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1681192532-15460-4-git-send-email-ssengar@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2023-04-14x86/hyperv: Mark hv_ghcb_terminate() as noreturnGuilherme G. Piccoli1-1/+1
Annotate the function prototype and definition as noreturn to prevent objtool warnings like: vmlinux.o: warning: objtool: hyperv_init+0x55c: unreachable instruction Also, as per Josh's suggestion, add it to the global_noreturns list. As a comparison, an objdump output without the annotation: [...] 1b63: mov $0x1,%esi 1b68: xor %edi,%edi 1b6a: callq ffffffff8102f680 <hv_ghcb_terminate> 1b6f: jmpq ffffffff82f217ec <hyperv_init+0x9c> # unreachable 1b74: cmpq $0xffffffffffffffff,-0x702a24(%rip) [...] Now, after adding the __noreturn to the function prototype: [...] 17df: callq ffffffff8102f6d0 <hv_ghcb_negotiate_protocol> 17e4: test %al,%al 17e6: je ffffffff82f21bb9 <hyperv_init+0x469> [...] <many insns> 1bb9: mov $0x1,%esi 1bbe: xor %edi,%edi 1bc0: callq ffffffff8102f680 <hv_ghcb_terminate> 1bc5: nopw %cs:0x0(%rax,%rax,1) # end of function Reported-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com> Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/32453a703dfcf0d007b473c9acbf70718222b74b.1681342859.git.jpoimboe@kernel.org
2023-03-27x86/hyperv: Change vTOM handling to use standard coco mechanismsMichael Kelley1-6/+10
Hyper-V guests on AMD SEV-SNP hardware have the option of using the "virtual Top Of Memory" (vTOM) feature specified by the SEV-SNP architecture. With vTOM, shared vs. private memory accesses are controlled by splitting the guest physical address space into two halves. vTOM is the dividing line where the uppermost bit of the physical address space is set; e.g., with 47 bits of guest physical address space, vTOM is 0x400000000000 (bit 46 is set). Guest physical memory is accessible at two parallel physical addresses -- one below vTOM and one above vTOM. Accesses below vTOM are private (encrypted) while accesses above vTOM are shared (decrypted). In this sense, vTOM is like the GPA.SHARED bit in Intel TDX. Support for Hyper-V guests using vTOM was added to the Linux kernel in two patch sets[1][2]. This support treats the vTOM bit as part of the physical address. For accessing shared (decrypted) memory, these patch sets create a second kernel virtual mapping that maps to physical addresses above vTOM. A better approach is to treat the vTOM bit as a protection flag, not as part of the physical address. This new approach is like the approach for the GPA.SHARED bit in Intel TDX. Rather than creating a second kernel virtual mapping, the existing mapping is updated using recently added coco mechanisms. When memory is changed between private and shared using set_memory_decrypted() and set_memory_encrypted(), the PTEs for the existing kernel mapping are changed to add or remove the vTOM bit in the guest physical address, just as with TDX. The hypercalls to change the memory status on the host side are made using the existing callback mechanism. Everything just works, with a minor tweak to map the IO-APIC to use private accesses. To accomplish the switch in approach, the following must be done: * Update Hyper-V initialization to set the cc_mask based on vTOM and do other coco initialization. * Update physical_mask so the vTOM bit is no longer treated as part of the physical address * Remove CC_VENDOR_HYPERV and merge the associated vTOM functionality under CC_VENDOR_AMD. Update cc_mkenc() and cc_mkdec() to set/clear the vTOM bit as a protection flag. * Code already exists to make hypercalls to inform Hyper-V about pages changing between shared and private. Update this code to run as a callback from __set_memory_enc_pgtable(). * Remove the Hyper-V special case from __set_memory_enc_dec() * Remove the Hyper-V specific call to swiotlb_update_mem_attributes() since mem_encrypt_init() will now do it. * Add a Hyper-V specific implementation of the is_private_mmio() callback that returns true for the IO-APIC and vTPM MMIO addresses [1] https://lore.kernel.org/all/20211025122116.264793-1-ltykernel@gmail.com/ [2] https://lore.kernel.org/all/20211213071407.314309-1-ltykernel@gmail.com/ [ bp: Touchups. ] Signed-off-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Link: https://lore.kernel.org/r/1679838727-87310-7-git-send-email-mikelley@microsoft.com
2023-02-16x86/hyperv: Fix hv_get/set_register for nested bringupNuno Das Neves1-4/+8
hv_get_nested_reg only translates SINT0, resulting in the wrong sint being registered by nested vmbus. Fix the issue with new utility function hv_is_sint_reg. While at it, improve clarity of hv_set_non_nested_register and hv_is_synic_reg. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Jinank Jain <jinankjain@linux.microsoft.com> Link: https://lore.kernel.org/r/1675980172-6851-1-git-send-email-nunodasneves@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2023-01-17x86/hyperv: Add an interface to do nested hypercallsJinank Jain1-4/+38
According to TLFS, in order to communicate to L0 hypervisor there needs to be an additional bit set in the control register. This communication is required to perform privileged instructions which can only be performed by L0 hypervisor. An example of that could be setting up the VMBus infrastructure. Signed-off-by: Jinank Jain <jinankjain@linux.microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/24f9d46d5259a688113e6e5e69e21002647f4949.1672639707.git.jinankjain@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2023-01-17Drivers: hv: Setup synic registers in case of nested root partitionJinank Jain1-24/+6
Child partitions are free to allocate SynIC message and event page but in case of root partition it must use the pages allocated by Microsoft Hypervisor (MSHV). Base address for these pages can be found using synthetic MSRs exposed by MSHV. There is a slight difference in those MSRs for nested vs non-nested root partition. Signed-off-by: Jinank Jain <jinankjain@linux.microsoft.com> Reviewed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/cb951fb1ad6814996fc54f4a255c5841a20a151f.1672639707.git.jinankjain@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2022-11-17clocksource/drivers/hyper-v: Include asm/hyperv-tlfs.h not asm/mshyperv.hThomas Gleixner1-2/+0
clocksource/hyperv_timer.h is included into the VDSO build. It includes asm/mshyperv.h which in turn includes the world and some more. This worked so far by chance, but any subtle change in the include chain results in a build breakage because VDSO builds are building user space libraries. Include asm/hyperv-tlfs.h instead which contains everything what the VDSO build needs except the hv_get_raw_timer() define. Move this define into a separate header file, which contains the prerequisites (msr.h) and is included by clocksource/hyperv_timer.h. Fixup drivers/hv/vmbus_drv.c which relies on the indirect include of asm/mshyperv.h. With that the VDSO build only pulls in the minimum requirements. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/87fsemtut0.ffs@tglx
2022-06-15x86/Hyper-V: Add SEV negotiate protocol support in Isolation VMTianyu Lan1-0/+4
Hyper-V Isolation VM current code uses sev_es_ghcb_hv_call() to read/write MSR via GHCB page and depends on the sev code. This may cause regression when sev code changes interface design. The latest SEV-ES code requires to negotiate GHCB version before reading/writing MSR via GHCB page and sev_es_ghcb_hv_call() doesn't work for Hyper-V Isolation VM. Add Hyper-V ghcb related implementation to decouple SEV and Hyper-V code. Negotiate GHCB version in the hyperv_init() and use the version to communicate with Hyper-V in the ghcb hv call function. Fixes: 2ea29c5abbc2 ("x86/sev: Save the negotiated GHCB version") Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20220614014553.1915929-1-ltykernel@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2022-01-16Merge tag 'hyperv-next-signed-20220114' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv updates from Wei Liu: - More patches for Hyper-V isolation VM support (Tianyu Lan) - Bug fixes and clean-up patches from various people * tag 'hyperv-next-signed-20220114' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: scsi: storvsc: Fix storvsc_queuecommand() memory leak x86/hyperv: Properly deal with empty cpumasks in hyperv_flush_tlb_multi() Drivers: hv: vmbus: Initialize request offers message for Isolation VM scsi: storvsc: Fix unsigned comparison to zero swiotlb: Add CONFIG_HAS_IOMEM check around swiotlb_mem_remap() x86/hyperv: Fix definition of hv_ghcb_pg variable Drivers: hv: Fix definition of hypercall input & output arg variables net: netvsc: Add Isolation VM support for netvsc driver scsi: storvsc: Add Isolation VM support for storvsc driver hyper-v: Enable swiotlb bounce buffer for Isolation VM x86/hyper-v: Add hyperv Isolation VM check in the cc_platform_has() swiotlb: Add swiotlb bounce buffer remap function for HV IVM
2022-01-12PCI: hv: Make the code arch neutral by adding arch specific interfacesSunil Muthuswamy1-7/+0
Encapsulate arch dependencies in Hyper-V vPCI through a set of arch-dependent interfaces. Adding these arch specific interfaces will allow for an implementation for other architectures, such as arm64. There are no functional changes expected from this patch. Link: https://lore.kernel.org/r/1641411156-31705-2-git-send-email-sunilmut@linux.microsoft.com Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com>
2021-12-28x86/hyperv: Fix definition of hv_ghcb_pg variableMichael Kelley1-1/+1
The percpu variable hv_ghcb_pg is incorrectly defined. The __percpu qualifier should be associated with the union hv_ghcb * (i.e., a pointer), not with the target of the pointer. This distinction makes no difference to gcc and the generated code, but sparse correctly complains. Fix the definition in the interest of general correctness in addition to making sparse happy. No functional change. Fixes: 0cc4f6d9f0b9 ("x86/hyperv: Initialize GHCB page in Isolation VM") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1640662315-22260-2-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-10-28x86/hyperv: Add Write/Read MSR registers via ghcb pageTianyu Lan1-14/+49
Hyperv provides GHCB protocol to write Synthetic Interrupt Controller MSR registers in Isolation VM with AMD SEV SNP and these registers are emulated by hypervisor directly. Hyperv requires to write SINTx MSR registers twice. First writes MSR via GHCB page to communicate with hypervisor and then writes wrmsr instruction to talk with paravisor which runs in VMPL0. Guest OS ID MSR also needs to be set via GHCB page. Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20211025122116.264793-7-ltykernel@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-10-28x86/hyperv: Add new hvcall guest address host visibility supportTianyu Lan1-1/+6
Add new hvcall guest address host visibility support to mark memory visible to host. Call it inside set_memory_decrypted /encrypted(). Add HYPERVISOR feature check in the hv_is_isolation_supported() to optimize in non-virtualization environment. Acked-by: Dave Hansen <dave.hansen@intel.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20211025122116.264793-4-ltykernel@gmail.com [ wei: fix conflicts with tip ] Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-10-28x86/hyperv: Initialize GHCB page in Isolation VMTianyu Lan1-0/+4
Hyperv exposes GHCB page via SEV ES GHCB MSR for SNP guest to communicate with hypervisor. Map GHCB page for all cpus to read/write MSR register and submit hvcall request via ghcb page. Reviewed-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Tianyu Lan <Tianyu.Lan@microsoft.com> Link: https://lore.kernel.org/r/20211025122116.264793-2-ltykernel@gmail.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-07-15Drivers: hv: Make portions of Hyper-V init code be arch neutralMichael Kelley1-4/+0
The code to allocate and initialize the hv_vp_index array is architecture neutral. Similarly, the code to allocate and populate the hypercall input and output arg pages is architecture neutral. Move both sets of code out from arch/x86 and into utility functions in drivers/hv/hv_common.c that can be shared by Hyper-V initialization on ARM64. No functional changes. However, the allocation of the hypercall input and output arg pages is done differently so that the size is always the Hyper-V page size, even if not the same as the guest page size (such as with ARM64's 64K page size). Signed-off-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1626287687-2045-2-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-04-21drivers: hv: Create a consistent pattern for checking Hyper-V hypercall statusJoseph Salisbury1-0/+1
There is not a consistent pattern for checking Hyper-V hypercall status. Existing code uses a number of variants. The variants work, but a consistent pattern would improve the readability of the code, and be more conformant to what the Hyper-V TLFS says about hypercall status. Implemented new helper functions hv_result(), hv_result_success(), and hv_repcomp(). Changed the places where hv_do_hypercall() and related variants are used to use the helper functions. Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1618620183-9967-2-git-send-email-joseph.salisbury@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-04-21x86/hyperv: Move hv_do_rep_hypercall to asm-genericJoseph Salisbury1-32/+0
This patch makes no functional changes. It simply moves hv_do_rep_hypercall() out of arch/x86/include/asm/mshyperv.h and into asm-generic/mshyperv.h hv_do_rep_hypercall() is architecture independent, so it makes sense that it should be in the architecture independent mshyperv.h, not in the x86-specific mshyperv.h. This is done in preperation for a follow up patch which creates a consistent pattern for checking Hyper-V hypercall status. Signed-off-by: Joseph Salisbury <joseph.salisbury@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/1618620183-9967-1-git-send-email-joseph.salisbury@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08clocksource/drivers/hyper-v: Move handling of STIMER0 interruptsMichael Kelley1-4/+0
STIMER0 interrupts are most naturally modeled as per-cpu IRQs. But because x86/x64 doesn't have per-cpu IRQs, the core STIMER0 interrupt handling machinery is done in code under arch/x86 and Linux IRQs are not used. Adding support for ARM64 means adding equivalent code using per-cpu IRQs under arch/arm64. A better model is to treat per-cpu IRQs as the normal path (which it is for modern architectures), and the x86/x64 path as the exception. Do this by incorporating standard Linux per-cpu IRQ allocation into the main SITMER0 driver code, and bypass it in the x86/x64 exception case. For x86/x64, special case code is retained under arch/x86, but no STIMER0 interrupt handling code is needed under arch/arm64. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/1614721102-2241-11-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08clocksource/drivers/hyper-v: Handle sched_clock differences inlineMichael Kelley1-11/+0
While the Hyper-V Reference TSC code is architecture neutral, the pv_ops.time.sched_clock() function is implemented for x86/x64, but not for ARM64. Current code calls a utility function under arch/x86 (and coming, under arch/arm64) to handle the difference. Change this approach to handle the difference inline based on whether GENERIC_SCHED_CLOCK is present. The new approach removes code under arch/* since the difference is tied more to the specifics of the Linux implementation than to the architecture. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/1614721102-2241-9-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08clocksource/drivers/hyper-v: Handle vDSO differences inlineMichael Kelley1-4/+0
While the driver for the Hyper-V Reference TSC and STIMERs is architecture neutral, vDSO is implemented for x86/x64, but not for ARM64. Current code calls into utility functions under arch/x86 (and coming, under arch/arm64) to handle the difference. Change this approach to handle the difference inline based on whether VDSO_CLOCK_MODE_HVCLOCK is present. The new approach removes code under arch/* since the difference is tied more to the specifics of the Linux implementation than to the architecture. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/1614721102-2241-8-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08Drivers: hv: vmbus: Move handling of VMbus interruptsMichael Kelley1-1/+0
VMbus interrupts are most naturally modelled as per-cpu IRQs. But because x86/x64 doesn't have per-cpu IRQs, the core VMbus interrupt handling machinery is done in code under arch/x86 and Linux IRQs are not used. Adding support for ARM64 means adding equivalent code using per-cpu IRQs under arch/arm64. A better model is to treat per-cpu IRQs as the normal path (which it is for modern architectures), and the x86/x64 path as the exception. Do this by incorporating standard Linux per-cpu IRQ allocation into the main VMbus driver, and bypassing it in the x86/x64 exception case. For x86/x64, special case code is retained under arch/x86, but no VMbus interrupt handling code is needed under arch/arm64. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/1614721102-2241-7-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08Drivers: hv: vmbus: Handle auto EOI quirk inlineMichael Kelley1-3/+0
On x86/x64, Hyper-V provides a flag to indicate auto EOI functionality, but it doesn't on ARM64. Handle this quirk inline instead of calling into code under arch/x86 (and coming, under arch/arm64). No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/1614721102-2241-6-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08Drivers: hv: Redo Hyper-V synthetic MSR get/set functionsMichael Kelley1-29/+10
Current code defines a separate get and set macro for each Hyper-V synthetic MSR used by the VMbus driver. Furthermore, the get macro can't be converted to a standard function because the second argument is modified in place, which is somewhat bad form. Redo this by providing a single get and a single set function that take a parameter specifying the MSR to be operated on. Fixup usage of the get function. Calling locations are no more complex than before, but the code under arch/x86 and the upcoming code under arch/arm64 is significantly simplified. Also standardize the names of Hyper-V synthetic MSRs that are architecture neutral. But keep the old x86-specific names as aliases that can be removed later when all references (particularly in KVM code) have been cleaned up in a separate patch series. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/1614721102-2241-4-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-03-08Drivers: hv: vmbus: Move Hyper-V page allocator to arch neutral codeMichael Kelley1-5/+0
The Hyper-V page allocator functions are implemented in an architecture neutral way. Move them into the architecture neutral VMbus module so a separate implementation for ARM64 is not needed. No functional change. Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/1614721102-2241-2-git-send-email-mikelley@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
2021-02-11iommu/hyperv: setup an IO-APIC IRQ remapping domain for root partitionWei Liu1-0/+4
Just like MSI/MSI-X, IO-APIC interrupts are remapped by Microsoft Hypervisor when Linux runs as the root partition. Implement an IRQ domain to handle mapping and unmapping of IO-APIC interrupts. Signed-off-by: Wei Liu <wei.liu@kernel.org> Acked-by: Joerg Roedel <joro@8bytes.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210203150435.27941-17-wei.liu@kernel.org
2021-02-11x86/hyperv: implement an MSI domain for root partitionWei Liu1-0/+2
When Linux runs as the root partition on Microsoft Hypervisor, its interrupts are remapped. Linux will need to explicitly map and unmap interrupts for hardware. Implement an MSI domain to issue the correct hypercalls. And initialize this irq domain as the default MSI irq domain. Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com> Co-Developed-by: Sunil Muthuswamy <sunilmut@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210203150435.27941-16-wei.liu@kernel.org
2021-02-11asm-generic/hyperv: update hv_msi_entryWei Liu1-2/+2
We will soon need to access fields inside the MSI address and MSI data fields. Introduce hv_msi_address_register and hv_msi_data_register. Fix up one user of hv_msi_entry in mshyperv.h. No functional change expected. Signed-off-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210203150435.27941-12-wei.liu@kernel.org
2021-02-11x86/hyperv: provide a bunch of helper functionsWei Liu1-0/+4
They are used to deposit pages into Microsoft Hypervisor and bring up logical and virtual processors. Signed-off-by: Lillian Grassin-Drake <ligrassi@microsoft.com> Signed-off-by: Sunil Muthuswamy <sunilmut@microsoft.com> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Co-Developed-by: Lillian Grassin-Drake <ligrassi@microsoft.com> Co-Developed-by: Sunil Muthuswamy <sunilmut@microsoft.com> Co-Developed-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210203150435.27941-10-wei.liu@kernel.org
2021-02-11x86/hyperv: extract partition ID from Microsoft Hypervisor if necessaryWei Liu1-0/+2
We will need the partition ID for executing some hypercalls later. Signed-off-by: Lillian Grassin-Drake <ligrassi@microsoft.com> Co-Developed-by: Sunil Muthuswamy <sunilmut@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210203150435.27941-7-wei.liu@kernel.org
2021-02-11x86/hyperv: allocate output arg pages if requiredWei Liu1-0/+1
When Linux runs as the root partition, it will need to make hypercalls which return data from the hypervisor. Allocate pages for storing results when Linux runs as the root partition. Signed-off-by: Lillian Grassin-Drake <ligrassi@microsoft.com> Co-Developed-by: Lillian Grassin-Drake <ligrassi@microsoft.com> Signed-off-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210203150435.27941-6-wei.liu@kernel.org
2021-02-11x86/hyperv: detect if Linux is the root partitionWei Liu1-0/+2
For now we can use the privilege flag to check. Stash the value to be used later. Put in a bunch of defines for future use when we want to have more fine-grained detection. Signed-off-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20210203150435.27941-3-wei.liu@kernel.org
2021-01-05x86/hyperv: Fix kexec panic/hang issuesDexuan Cui1-0/+2
Currently the kexec kernel can panic or hang due to 2 causes: 1) hv_cpu_die() is not called upon kexec, so the hypervisor corrupts the old VP Assist Pages when the kexec kernel runs. The same issue is fixed for hibernation in commit 421f090c819d ("x86/hyperv: Suspend/resume the VP assist page for hibernation"). Now fix it for kexec. 2) hyperv_cleanup() is called too early. In the kexec path, the other CPUs are stopped in hv_machine_shutdown() -> native_machine_shutdown(), so between hv_kexec_handler() and native_machine_shutdown(), the other CPUs can still try to access the hypercall page and cause panic. The workaround "hv_hypercall_pg = NULL;" in hyperv_cleanup() is unreliabe. Move hyperv_cleanup() to a better place. Signed-off-by: Dexuan Cui <decui@microsoft.com> Reviewed-by: Michael Kelley <mikelley@microsoft.com> Link: https://lore.kernel.org/r/20201222065541.24312-1-decui@microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org>
generated by cgit v1.2.3 (git 2.39.0) at 2024-08-17 00:35:46 +0300