From: Maxim Levitsky <mlevitsk@redhat.com>
To: Vitaly Kuznetsov <vkuznets@redhat.com>,
kvm@vger.kernel.org, Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 4/7] KVM: nVMX: Force enlightened VMCS sync from nested_vmx_failValid()
Date: Mon, 24 May 2021 15:27:47 +0300 [thread overview]
Message-ID: <03eb61e5365566ea2abcb54896263f88e1fcaf92.camel@redhat.com> (raw)
In-Reply-To: <20210517135054.1914802-5-vkuznets@redhat.com>
On Mon, 2021-05-17 at 15:50 +0200, Vitaly Kuznetsov wrote:
> 'need_vmcs12_to_shadow_sync' is used for both shadow and enlightened
> VMCS sync when we exit to L1. The comment in nested_vmx_failValid()
> validly states why shadow vmcs sync can be omitted but this doesn't
> apply to enlightened VMCS as it 'shadows' all VMCS12 fields.
>
> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---
> arch/x86/kvm/vmx/nested.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
> index ec476f64df73..eb2d25a93356 100644
> --- a/arch/x86/kvm/vmx/nested.c
> +++ b/arch/x86/kvm/vmx/nested.c
> @@ -194,9 +194,13 @@ static int nested_vmx_failValid(struct kvm_vcpu *vcpu,
> | X86_EFLAGS_ZF);
> get_vmcs12(vcpu)->vm_instruction_error = vm_instruction_error;
> /*
> - * We don't need to force a shadow sync because
> - * VM_INSTRUCTION_ERROR is not shadowed
> + * We don't need to force sync to shadow VMCS because
> + * VM_INSTRUCTION_ERROR is not shadowed. Enlightened VMCS 'shadows' all
> + * fields and thus must be synced.
> */
> + if (nested_evmcs_is_used(to_vmx(vcpu)))
> + to_vmx(vcpu)->nested.need_vmcs12_to_shadow_sync = true;
Cool, this is a bug that I noticed too while reviewing
previous patches in this series.
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Best regards,
Maxim Levitsky
> +
> return kvm_skip_emulated_instruction(vcpu);
> }
>
next prev parent reply other threads:[~2021-05-24 12:27 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-17 13:50 [PATCH v2 0/7] KVM: nVMX: Fixes for nested state migration when eVMCS is in use Vitaly Kuznetsov
2021-05-17 13:50 ` [PATCH v2 1/7] KVM: nVMX: Introduce nested_evmcs_is_used() Vitaly Kuznetsov
2021-05-24 12:11 ` Maxim Levitsky
2021-05-24 12:35 ` Vitaly Kuznetsov
2021-05-26 14:34 ` Maxim Levitsky
2021-05-27 7:54 ` Vitaly Kuznetsov
2021-05-27 14:10 ` Maxim Levitsky
2021-05-24 13:54 ` Paolo Bonzini
2021-05-24 14:09 ` Vitaly Kuznetsov
2021-05-24 14:18 ` Paolo Bonzini
2021-05-24 14:37 ` Vitaly Kuznetsov
2021-05-17 13:50 ` [PATCH v2 2/7] KVM: nVMX: Release enlightened VMCS on VMCLEAR Vitaly Kuznetsov
2021-05-24 12:13 ` Maxim Levitsky
2021-05-17 13:50 ` [PATCH v2 3/7] KVM: nVMX: Ignore 'hv_clean_fields' data when eVMCS data is copied in vmx_get_nested_state() Vitaly Kuznetsov
2021-05-24 12:26 ` Maxim Levitsky
2021-05-24 13:01 ` Vitaly Kuznetsov
2021-05-24 13:58 ` Paolo Bonzini
2021-05-26 14:44 ` Maxim Levitsky
2021-05-24 13:56 ` Paolo Bonzini
2021-05-24 14:12 ` Vitaly Kuznetsov
2021-05-17 13:50 ` [PATCH v2 4/7] KVM: nVMX: Force enlightened VMCS sync from nested_vmx_failValid() Vitaly Kuznetsov
2021-05-24 12:27 ` Maxim Levitsky [this message]
2021-05-17 13:50 ` [PATCH v2 5/7] KVM: nVMX: Reset eVMCS clean fields data from prepare_vmcs02() Vitaly Kuznetsov
2021-05-24 12:34 ` Maxim Levitsky
2021-05-24 13:07 ` Vitaly Kuznetsov
2021-05-17 13:50 ` [PATCH v2 6/7] KVM: nVMX: Request to sync eVMCS from VMCS12 after migration Vitaly Kuznetsov
2021-05-24 12:35 ` Maxim Levitsky
2021-05-17 13:50 ` [PATCH v2 7/7] KVM: selftests: evmcs_test: Test that KVM_STATE_NESTED_EVMCS is never lost Vitaly Kuznetsov
2021-05-24 12:36 ` Maxim Levitsky
2021-05-24 12:08 ` [PATCH v2 0/7] KVM: nVMX: Fixes for nested state migration when eVMCS is in use Maxim Levitsky
2021-05-24 12:44 ` Vitaly Kuznetsov
2021-05-26 14:41 ` Maxim Levitsky
2021-05-27 8:01 ` Vitaly Kuznetsov
2021-05-27 14:11 ` Maxim Levitsky
2021-05-27 14:17 ` Paolo Bonzini
2021-05-24 14:01 ` Paolo Bonzini
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