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| author | Sean Christopherson <seanjc@google.com> | 2021-09-21 03:02:58 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2021-09-30 11:27:06 +0300 |
| commit | e8f65b9bb4832028cdbd5927ddb67f66c6ccdd27 (patch) | |
| tree | f1c2ab66876ea37e1b5dd4da20438d075ebe5a3a /arch/x86/kvm | |
| parent | 5ebbc470d7f33e8fba6bdb2ac8e62c49cec99108 (diff) | |
| download | linux-e8f65b9bb4832028cdbd5927ddb67f66c6ccdd27.tar.xz | |
KVM: x86: Remove defunct setting of XCR0 for guest during vCPU create
Drop code to initialize XCR0 during fx_init(), a.k.a. vCPU creation, as
XCR0 has been initialized during kvm_vcpu_reset() (for RESET) since
commit a554d207dc46 ("KVM: X86: Processor States following Reset or INIT").
Back when XCR0 support was added by commit 2acf923e38fb ("KVM: VMX:
Enable XSAVE/XRSTOR for guest"), KVM didn't differentiate between RESET
and INIT. Ignoring the fact that calling fx_init() for INIT is obviously
wrong, e.g. FPU state after INIT is not the same as after RESET, setting
XCR0 in fx_init() was correct.
Eventually fx_init() got moved to kvm_arch_vcpu_init(), a.k.a. vCPU
creation (ignore the terrible name) by commit 0ee6a5172573 ("x86/fpu,
kvm: Simplify fx_init()"). Finally, commit 95a0d01eef7a ("KVM: x86: Move
all vcpu init code into kvm_arch_vcpu_create()") killed off
kvm_arch_vcpu_init(), leaving behind the oddity of redundant setting of
guest state during vCPU creation.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210921000303.400537-6-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm')
| -rw-r--r-- | arch/x86/kvm/x86.c | 7 |
1 files changed, 1 insertions, 6 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 69d656125103..da0d48d10769 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -973,7 +973,7 @@ static int __kvm_set_xcr(struct kvm_vcpu *vcpu, u32 index, u64 xcr) /* * Do not allow the guest to set bits that we do not support * saving. However, xcr0 bit 0 is always set, even if the - * emulated CPU does not support XSAVE (see fx_init). + * emulated CPU does not support XSAVE (see kvm_vcpu_reset()). */ valid_bits = vcpu->arch.guest_supported_xcr0 | XFEATURE_MASK_FP; if (xcr0 & ~valid_bits) @@ -10606,11 +10606,6 @@ static void fx_init(struct kvm_vcpu *vcpu) if (boot_cpu_has(X86_FEATURE_XSAVES)) vcpu->arch.guest_fpu->state.xsave.header.xcomp_bv = host_xcr0 | XSTATE_COMPACTION_ENABLED; - - /* - * Ensure guest xcr0 is valid for loading - */ - vcpu->arch.xcr0 = XFEATURE_MASK_FP; } void kvm_free_guest_fpu(struct kvm_vcpu *vcpu) |