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| author |  Sean Christopherson <seanjc@google.com>
| 2022-08-31 00:07:21 +0000 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com>
| 2022-11-30 16:27:17 -0800 |
| commit | 4a8fd4a720f8a8dbc370076d26388176c311218a (patch) | |
| tree | fd3c45f2fb83ace1366bc65988712c35220d54ea /arch/x86/kvm/vmx/nested.c | |
| parent | KVM: x86: Clean up KVM_CAP_X86_USER_SPACE_MSR documentation (diff) | |
| download | linux-4a8fd4a720f8a8dbc370076d26388176c311218a.tar.gz linux-4a8fd4a720f8a8dbc370076d26388176c311218a.tar.bz2 linux-4a8fd4a720f8a8dbc370076d26388176c311218a.zip | |
KVM: nVMX: Reword comments about generating nested CR0/4 read shadows
Reword the comments that (attempt to) document nVMX's overrides of the
CR0/4 read shadows for L2 after calling vmx_set_cr0/4(). The important
behavior that needs to be documented is that KVM needs to override the
shadows to account for L1's masks even though the shadows are set by the
common helpers (and that setting the shadows first would result in the
correct shadows being clobbered).
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Link: https://lore.kernel.org/r/20220831000721.4066617-1-seanjc@google.com
Diffstat (limited to 'arch/x86/kvm/vmx/nested.c')
| -rw-r--r-- | arch/x86/kvm/vmx/nested.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 61c83424285c..b6f4411b613e 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2588,12 +2588,9 @@ static int prepare_vmcs02(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12, nested_ept_init_mmu_context(vcpu); /* - * This sets GUEST_CR0 to vmcs12->guest_cr0, possibly modifying those - * bits which we consider mandatory enabled. - * The CR0_READ_SHADOW is what L2 should have expected to read given - * the specifications by L1; It's not enough to take - * vmcs12->cr0_read_shadow because on our cr0_guest_host_mask we - * have more bits than L1 expected. + * Override the CR0/CR4 read shadows after setting the effective guest + * CR0/CR4. The common helpers also set the shadows, but they don't + * account for vmcs12's cr0/4_guest_host_mask. */ vmx_set_cr0(vcpu, vmcs12->guest_cr0); vmcs_writel(CR0_READ_SHADOW, nested_read_cr0(vmcs12)); |