From: Sean Christopherson Date: Fri, 11 Oct 2024 02:10:43 +0000 (-0700) Subject: KVM: x86/mmu: Set shadow_dirty_mask for EPT even if A/D bits disabled X-Git-Tag: v6.13-rc1~97^2~13^2~17 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=53510b912518bd15dba9632ee8e539168166af3c;p=thirdparty%2Fkernel%2Flinux.git KVM: x86/mmu: Set shadow_dirty_mask for EPT even if A/D bits disabled Set shadow_dirty_mask to the architectural EPT Dirty bit value even if A/D bits are disabled at the module level, i.e. even if KVM will never enable A/D bits in hardware. Doing so provides consistent behavior for Accessed and Dirty bits, i.e. doesn't leave KVM in a state where it sets shadow_accessed_mask but not shadow_dirty_mask. Functionally, this should be one big nop, as consumption of shadow_dirty_mask is always guarded by a check that hardware A/D bits are enabled. Link: https://lore.kernel.org/r/20241011021051.1557902-12-seanjc@google.com Signed-off-by: Sean Christopherson --- diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c index e352d18213190..54d8c9b760506 100644 --- a/arch/x86/kvm/mmu/spte.c +++ b/arch/x86/kvm/mmu/spte.c @@ -420,7 +420,7 @@ void kvm_mmu_set_ept_masks(bool has_ad_bits, bool has_exec_only) shadow_user_mask = VMX_EPT_READABLE_MASK; shadow_accessed_mask = VMX_EPT_ACCESS_BIT; - shadow_dirty_mask = has_ad_bits ? VMX_EPT_DIRTY_BIT : 0ull; + shadow_dirty_mask = VMX_EPT_DIRTY_BIT; shadow_nx_mask = 0ull; shadow_x_mask = VMX_EPT_EXECUTABLE_MASK; /* VMX_EPT_SUPPRESS_VE_BIT is needed for W or X violation. */