From 339f5a7fb2d6350fdb11f067da5240fd97e4f284 Mon Sep 17 00:00:00 2001 From: Rick Edgecombe Date: Thu, 3 Dec 2020 15:11:20 -0800 Subject: [PATCH] kvm: x86/mmu: Use cpuid to determine max gfn In the TDP MMU, use shadow_phys_bits to dermine the maximum possible GFN mapped in the guest for zapping operations. boot_cpu_data.x86_phys_bits may be reduced in the case of HW features that steal HPA bits for other purposes. However, this doesn't necessarily reduce GPA space that can be accessed via TDP. So zap based on a maximum gfn calculated with MAXPHYADDR retrieved from CPUID. This is already stored in shadow_phys_bits, so use it instead of x86_phys_bits. Fixes: faaf05b00aec ("kvm: x86/mmu: Support zapping SPTEs in the TDP MMU") Signed-off-by: Rick Edgecombe Message-Id: <20201203231120.27307-1-rick.p.edgecombe@intel.com> Reviewed-by: Sean Christopherson Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu/tdp_mmu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index ff28a5c6abd6..84c8f06bec26 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -66,7 +66,7 @@ static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root, void kvm_tdp_mmu_free_root(struct kvm *kvm, struct kvm_mmu_page *root) { - gfn_t max_gfn = 1ULL << (boot_cpu_data.x86_phys_bits - PAGE_SHIFT); + gfn_t max_gfn = 1ULL << (shadow_phys_bits - PAGE_SHIFT); lockdep_assert_held(&kvm->mmu_lock); @@ -456,7 +456,7 @@ bool kvm_tdp_mmu_zap_gfn_range(struct kvm *kvm, gfn_t start, gfn_t end) void kvm_tdp_mmu_zap_all(struct kvm *kvm) { - gfn_t max_gfn = 1ULL << (boot_cpu_data.x86_phys_bits - PAGE_SHIFT); + gfn_t max_gfn = 1ULL << (shadow_phys_bits - PAGE_SHIFT); bool flush; flush = kvm_tdp_mmu_zap_gfn_range(kvm, 0, max_gfn); -- 2.11.0