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author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-08-05 00:59:54 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-08-05 00:59:54 +0300 |
commit | 7c5c3a6177fa9646884114fc7f2e970b0bc50dc9 (patch) | |
tree | 956857522574ae7cb07d2227dc16e53d7e9e00e7 /Documentation/virt/kvm/s390 | |
parent | f0a892f599c46af673e47418c47c15e69a7b67f4 (diff) | |
parent | 281106f938d3daaea6f8b6723a8217a2a1ef6936 (diff) | |
download | linux-7c5c3a6177fa9646884114fc7f2e970b0bc50dc9.tar.xz |
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm updates from Paolo Bonzini:
"Quite a large pull request due to a selftest API overhaul and some
patches that had come in too late for 5.19.
ARM:
- Unwinder implementations for both nVHE modes (classic and
protected), complete with an overflow stack
- Rework of the sysreg access from userspace, with a complete rewrite
of the vgic-v3 view to allign with the rest of the infrastructure
- Disagregation of the vcpu flags in separate sets to better track
their use model.
- A fix for the GICv2-on-v3 selftest
- A small set of cosmetic fixes
RISC-V:
- Track ISA extensions used by Guest using bitmap
- Added system instruction emulation framework
- Added CSR emulation framework
- Added gfp_custom flag in struct kvm_mmu_memory_cache
- Added G-stage ioremap() and iounmap() functions
- Added support for Svpbmt inside Guest
s390:
- add an interface to provide a hypervisor dump for secure guests
- improve selftests to use TAP interface
- enable interpretive execution of zPCI instructions (for PCI
passthrough)
- First part of deferred teardown
- CPU Topology
- PV attestation
- Minor fixes
x86:
- Permit guests to ignore single-bit ECC errors
- Intel IPI virtualization
- Allow getting/setting pending triple fault with
KVM_GET/SET_VCPU_EVENTS
- PEBS virtualization
- Simplify PMU emulation by just using PERF_TYPE_RAW events
- More accurate event reinjection on SVM (avoid retrying
instructions)
- Allow getting/setting the state of the speaker port data bit
- Refuse starting the kvm-intel module if VM-Entry/VM-Exit controls
are inconsistent
- "Notify" VM exit (detect microarchitectural hangs) for Intel
- Use try_cmpxchg64 instead of cmpxchg64
- Ignore benign host accesses to PMU MSRs when PMU is disabled
- Allow disabling KVM's "MONITOR/MWAIT are NOPs!" behavior
- Allow NX huge page mitigation to be disabled on a per-vm basis
- Port eager page splitting to shadow MMU as well
- Enable CMCI capability by default and handle injected UCNA errors
- Expose pid of vcpu threads in debugfs
- x2AVIC support for AMD
- cleanup PIO emulation
- Fixes for LLDT/LTR emulation
- Don't require refcounted "struct page" to create huge SPTEs
- Miscellaneous cleanups:
- MCE MSR emulation
- Use separate namespaces for guest PTEs and shadow PTEs bitmasks
- PIO emulation
- Reorganize rmap API, mostly around rmap destruction
- Do not workaround very old KVM bugs for L0 that runs with nesting enabled
- new selftests API for CPUID
Generic:
- Fix races in gfn->pfn cache refresh; do not pin pages tracked by
the cache
- new selftests API using struct kvm_vcpu instead of a (vm, id)
tuple"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (606 commits)
selftests: kvm: set rax before vmcall
selftests: KVM: Add exponent check for boolean stats
selftests: KVM: Provide descriptive assertions in kvm_binary_stats_test
selftests: KVM: Check stat name before other fields
KVM: x86/mmu: remove unused variable
RISC-V: KVM: Add support for Svpbmt inside Guest/VM
RISC-V: KVM: Use PAGE_KERNEL_IO in kvm_riscv_gstage_ioremap()
RISC-V: KVM: Add G-stage ioremap() and iounmap() functions
KVM: Add gfp_custom flag in struct kvm_mmu_memory_cache
RISC-V: KVM: Add extensible CSR emulation framework
RISC-V: KVM: Add extensible system instruction emulation framework
RISC-V: KVM: Factor-out instruction emulation into separate sources
RISC-V: KVM: move preempt_disable() call in kvm_arch_vcpu_ioctl_run
RISC-V: KVM: Make kvm_riscv_guest_timer_init a void function
RISC-V: KVM: Fix variable spelling mistake
RISC-V: KVM: Improve ISA extension by using a bitmap
KVM, x86/mmu: Fix the comment around kvm_tdp_mmu_zap_leafs()
KVM: SVM: Dump Virtual Machine Save Area (VMSA) to klog
KVM: x86/mmu: Treat NX as a valid SPTE bit for NPT
KVM: x86: Do not block APIC write for non ICR registers
...
Diffstat (limited to 'Documentation/virt/kvm/s390')
-rw-r--r-- | Documentation/virt/kvm/s390/index.rst | 1 | ||||
-rw-r--r-- | Documentation/virt/kvm/s390/s390-pv-dump.rst | 64 |
2 files changed, 65 insertions, 0 deletions
diff --git a/Documentation/virt/kvm/s390/index.rst b/Documentation/virt/kvm/s390/index.rst index 605f488f0cc5..44ec9ab14b59 100644 --- a/Documentation/virt/kvm/s390/index.rst +++ b/Documentation/virt/kvm/s390/index.rst @@ -10,3 +10,4 @@ KVM for s390 systems s390-diag s390-pv s390-pv-boot + s390-pv-dump diff --git a/Documentation/virt/kvm/s390/s390-pv-dump.rst b/Documentation/virt/kvm/s390/s390-pv-dump.rst new file mode 100644 index 000000000000..e542f06048f3 --- /dev/null +++ b/Documentation/virt/kvm/s390/s390-pv-dump.rst @@ -0,0 +1,64 @@ +.. SPDX-License-Identifier: GPL-2.0 + +=========================================== +s390 (IBM Z) Protected Virtualization dumps +=========================================== + +Summary +------- + +Dumping a VM is an essential tool for debugging problems inside +it. This is especially true when a protected VM runs into trouble as +there's no way to access its memory and registers from the outside +while it's running. + +However when dumping a protected VM we need to maintain its +confidentiality until the dump is in the hands of the VM owner who +should be the only one capable of analysing it. + +The confidentiality of the VM dump is ensured by the Ultravisor who +provides an interface to KVM over which encrypted CPU and memory data +can be requested. The encryption is based on the Customer +Communication Key which is the key that's used to encrypt VM data in a +way that the customer is able to decrypt. + + +Dump process +------------ + +A dump is done in 3 steps: + +**Initiation** + +This step initializes the dump process, generates cryptographic seeds +and extracts dump keys with which the VM dump data will be encrypted. + +**Data gathering** + +Currently there are two types of data that can be gathered from a VM: +the memory and the vcpu state. + +The vcpu state contains all the important registers, general, floating +point, vector, control and tod/timers of a vcpu. The vcpu dump can +contain incomplete data if a vcpu is dumped while an instruction is +emulated with help of the hypervisor. This is indicated by a flag bit +in the dump data. For the same reason it is very important to not only +write out the encrypted vcpu state, but also the unencrypted state +from the hypervisor. + +The memory state is further divided into the encrypted memory and its +metadata comprised of the encryption tweaks and status flags. The +encrypted memory can simply be read once it has been exported. The +time of the export does not matter as no re-encryption is +needed. Memory that has been swapped out and hence was exported can be +read from the swap and written to the dump target without need for any +special actions. + +The tweaks / status flags for the exported pages need to be requested +from the Ultravisor. + +**Finalization** + +The finalization step will provide the data needed to be able to +decrypt the vcpu and memory data and end the dump process. When this +step completes successfully a new dump initiation can be started. |