| Date | Tue, 13 Jul 2021 09:32:45 -0700 | Subject | [PATCH v2 07/46] KVM: VMX: Remove explicit MMU reset in enter_rmode() | From | Sean Christopherson <> |
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Drop an explicit MMU reset when entering emulated real mode now that the vCPU INIT/RESET path correctly handles conditional MMU resets, e.g. if INIT arrives while the vCPU is in 64-bit mode.
Note, while there are multiple other direct calls to vmx_set_cr0(), i.e. paths that change CR0 without invoking kvm_post_set_cr0(), only the INIT emulation can reach enter_rmode(). CLTS emulation only toggles CR.TS, VM-Exit (and late VM-Fail) emulation cannot architecturally transition to Real Mode, and VM-Enter to Real Mode is possible if and only if Unrestricted Guest is enabled (exposed to L1).
This effectively reverts commit 8668a3c468ed ("KVM: VMX: Reset mmu context when entering real mode")
Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/x86/kvm/vmx/vmx.c | 2 -- 1 file changed, 2 deletions(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 825197f21700..0f5e97a904e5 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -2852,8 +2852,6 @@ static void enter_rmode(struct kvm_vcpu *vcpu) fix_rmode_seg(VCPU_SREG_DS, &vmx->rmode.segs[VCPU_SREG_DS]); fix_rmode_seg(VCPU_SREG_GS, &vmx->rmode.segs[VCPU_SREG_GS]); fix_rmode_seg(VCPU_SREG_FS, &vmx->rmode.segs[VCPU_SREG_FS]); - - kvm_mmu_reset_context(vcpu); } int vmx_set_efer(struct kvm_vcpu *vcpu, u64 efer) -- 2.32.0.93.g670b81a890-goog
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