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authorSean Christopherson <sean.j.christopherson@intel.com>2019-12-07 02:57:14 +0300
committerPaolo Bonzini <pbonzini@redhat.com>2020-01-08 20:16:02 +0300
commit736c291c9f36b07f8889c61764c28edce20e715d (patch)
tree4cd8d7f851dc796efe60fbae2b4ef692e40e8acc /arch/x86/kernel/tsc_sync.c
parent95145c25a78cc0a9d3cbc75708abde432310c5a1 (diff)
downloadlinux-736c291c9f36b07f8889c61764c28edce20e715d.tar.xz
KVM: x86: Use gpa_t for cr2/gpa to fix TDP support on 32-bit KVM
Convert a plethora of parameters and variables in the MMU and page fault flows from type gva_t to gpa_t to properly handle TDP on 32-bit KVM. Thanks to PSE and PAE paging, 32-bit kernels can access 64-bit physical addresses. When TDP is enabled, the fault address is a guest physical address and thus can be a 64-bit value, even when both KVM and its guest are using 32-bit virtual addressing, e.g. VMX's VMCS.GUEST_PHYSICAL is a 64-bit field, not a natural width field. Using a gva_t for the fault address means KVM will incorrectly drop the upper 32-bits of the GPA. Ditto for gva_to_gpa() when it is used to translate L2 GPAs to L1 GPAs. Opportunistically rename variables and parameters to better reflect the dual address modes, e.g. use "cr2_or_gpa" for fault addresses and plain "addr" instead of "vaddr" when the address may be either a GVA or an L2 GPA. Similarly, use "gpa" in the nonpaging_page_fault() flows to avoid a confusing "gpa_t gva" declaration; this also sets the stage for a future patch to combing nonpaging_page_fault() and tdp_page_fault() with minimal churn. Sprinkle in a few comments to document flows where an address is known to be a GVA and thus can be safely truncated to a 32-bit value. Add WARNs in kvm_handle_page_fault() and FNAME(gva_to_gpa_nested)() to help document such cases and detect bugs. Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kernel/tsc_sync.c')
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