From: Paolo Bonzini <pbonzini@redhat.com>
To: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
vkuznets@redhat.com, Joerg Roedel <jroedel@suse.de>
Subject: Re: [PATCH 21/24] KVM: x86: always update CR3 in VMCB
Date: Wed, 20 May 2020 22:14:47 +0200 [thread overview]
Message-ID: <d85c2e1d-93b3-186d-7df4-80ae6aa03618@redhat.com> (raw)
In-Reply-To: <20200520182202.GB18102@linux.intel.com>
On 20/05/20 20:22, Sean Christopherson wrote:
> As an alternative fix, what about marking VCPU_EXREG_CR3 dirty in
> __set_sregs()? E.g.
>
> /*
> * Loading vmcs02.GUEST_CR3 is handled by nested VM-Enter, but
> * it can be explicitly dirtied by KVM_SET_SREGS.
> */
> if (is_guest_mode(vcpu) &&
> !test_bit(VCPU_EXREG_CR3, (ulong *)&vcpu->arch.regs_dirty))
>
> There's already a dependency on __set_sregs() doing
> kvm_register_mark_available() before kvm_mmu_reset_context(), i.e. the
> code is already a bit kludgy. The dirty check would make the kludge less
> subtle and provide explicit documentation.
A comment in __set_sregs is certainly a good idea. But checking for
dirty seems worse since the caching of CR3 is a bit special in this
respect (it's never marked dirty).
This patch should probably be split too, so that the Fixes tags are
separate for Intel and AMD.
Paolo
>> guest_cr3 = vcpu->arch.cr3;
>
> The comment that's just below the context is now stale, e.g. replace
> vmcs01.GUEST_CR3 with vmcs.GUEST_CR3.
>
>> --
>> 2.18.2
>>
>>
>
next prev parent reply other threads:[~2020-05-20 20:14 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-20 17:21 [PATCH 00/24] KVM: nSVM: event fixes and migration support Paolo Bonzini
2020-05-20 17:21 ` [PATCH 01/24] KVM: nSVM: fix condition for filtering async PF Paolo Bonzini
2020-05-26 0:23 ` Sasha Levin
2020-05-20 17:21 ` [PATCH 02/24] KVM: nSVM: leave ASID aside in copy_vmcb_control_area Paolo Bonzini
2020-05-26 0:23 ` Sasha Levin
2020-05-20 17:21 ` [PATCH 03/24] KVM: nSVM: inject exceptions via svm_check_nested_events Paolo Bonzini
2020-05-20 17:21 ` [PATCH 04/24] KVM: nSVM: remove exit_required Paolo Bonzini
2020-05-20 17:21 ` [PATCH 05/24] KVM: nSVM: correctly inject INIT vmexits Paolo Bonzini
2020-05-20 17:21 ` [PATCH 06/24] KVM: nSVM: move map argument out of enter_svm_guest_mode Paolo Bonzini
2020-05-20 17:21 ` [PATCH 07/24] KVM: nSVM: extract load_nested_vmcb_control Paolo Bonzini
2020-05-20 17:21 ` [PATCH 08/24] KVM: nSVM: extract preparation of VMCB for nested run Paolo Bonzini
2020-05-20 17:21 ` [PATCH 09/24] KVM: nSVM: clean up tsc_offset update Paolo Bonzini
2020-05-20 17:21 ` [PATCH 10/24] KVM: nSVM: pass vmcb_control_area to copy_vmcb_control_area Paolo Bonzini
2020-05-20 17:21 ` [PATCH 11/24] KVM: nSVM: remove trailing padding for struct vmcb_control_area Paolo Bonzini
2020-05-20 17:21 ` [PATCH 12/24] KVM: nSVM: save all control fields in svm->nested Paolo Bonzini
2020-05-20 17:21 ` [PATCH 13/24] KVM: nSVM: do not reload pause filter fields from VMCB Paolo Bonzini
2020-05-20 17:21 ` [PATCH 14/24] KVM: nSVM: remove HF_VINTR_MASK Paolo Bonzini
2020-05-20 17:21 ` [PATCH 15/24] KVM: nSVM: remove HF_HIF_MASK Paolo Bonzini
2020-05-20 17:21 ` [PATCH 16/24] KVM: nSVM: split nested_vmcb_check_controls Paolo Bonzini
2020-05-20 17:21 ` [PATCH 17/24] KVM: nSVM: do all MMU switch work in init/uninit functions Paolo Bonzini
2020-05-20 17:21 ` [PATCH 18/24] KVM: nSVM: leave guest mode when clearing EFER.SVME Paolo Bonzini
2020-05-20 17:21 ` [PATCH 19/24] KVM: nSVM: extract svm_set_gif Paolo Bonzini
2020-05-20 17:21 ` [PATCH 20/24] KVM: MMU: pass arbitrary CR0/CR4/EFER to kvm_init_shadow_mmu Paolo Bonzini
2020-05-20 17:21 ` [PATCH 21/24] KVM: x86: always update CR3 in VMCB Paolo Bonzini
2020-05-20 18:22 ` Sean Christopherson
2020-05-20 20:14 ` Paolo Bonzini [this message]
2020-05-22 22:47 ` Sean Christopherson
2020-05-23 7:07 ` Paolo Bonzini
2020-05-20 18:24 ` Sean Christopherson
2020-05-20 17:21 ` [PATCH 22/24] uaccess: add memzero_user Paolo Bonzini
2020-05-20 20:40 ` Christoph Hellwig
2020-05-20 20:50 ` Al Viro
2020-05-20 21:13 ` Paolo Bonzini
2020-05-20 21:28 ` Al Viro
2020-05-20 21:33 ` Paolo Bonzini
2020-05-20 17:21 ` [PATCH 23/24] selftests: kvm: add a SVM version of state-test Paolo Bonzini
2020-05-20 17:21 ` [PATCH 24/24] KVM: nSVM: implement KVM_GET_NESTED_STATE and KVM_SET_NESTED_STATE Paolo Bonzini
2020-05-20 19:24 ` [PATCH 00/24] KVM: nSVM: event fixes and migration support Maxim Levitsky
2020-05-20 20:42 ` Paolo Bonzini
2020-05-20 21:08 ` Maxim Levitsky
2020-05-20 21:15 ` Paolo Bonzini
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