From: Paolo Bonzini <pbonzini@redhat.com>
To: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
kvm@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 3/3] KVM: x86: Move #PF retry tracking variables into emulation context
Date: Wed, 19 Feb 2020 09:13:00 +0100 [thread overview]
Message-ID: <40c8d560-1a5d-d592-5682-720980ca3dd9@redhat.com> (raw)
In-Reply-To: <20200218230310.29410-4-sean.j.christopherson@intel.com>
On 19/02/20 00:03, Sean Christopherson wrote:
> Move last_retry_eip and last_retry_addr into the emulation context as
> they are specific to retrying an instruction after emulation failure.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
I'm not sure about this, since it's not used by emulate.c. The other
two patches are good.
Paolo
> ---
> arch/x86/include/asm/kvm_emulate.h | 4 ++++
> arch/x86/include/asm/kvm_host.h | 3 ---
> arch/x86/kvm/x86.c | 11 ++++++-----
> 3 files changed, 10 insertions(+), 8 deletions(-)
>
> diff --git a/arch/x86/include/asm/kvm_emulate.h b/arch/x86/include/asm/kvm_emulate.h
> index a4ef19a6e612..a26c8de414e8 100644
> --- a/arch/x86/include/asm/kvm_emulate.h
> +++ b/arch/x86/include/asm/kvm_emulate.h
> @@ -315,6 +315,10 @@ struct x86_emulate_ctxt {
> bool gpa_available;
> gpa_t gpa_val;
>
> + /* Track EIP and CR2/GPA when retrying faulting instruction on #PF. */
> + unsigned long last_retry_eip;
> + unsigned long last_retry_addr;
> +
> /*
> * decode cache
> */
> diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
> index 9c79c41eb5f6..6312ea32bb41 100644
> --- a/arch/x86/include/asm/kvm_host.h
> +++ b/arch/x86/include/asm/kvm_host.h
> @@ -752,9 +752,6 @@ struct kvm_vcpu_arch {
>
> cpumask_var_t wbinvd_dirty_mask;
>
> - unsigned long last_retry_eip;
> - unsigned long last_retry_addr;
> -
> struct {
> bool halted;
> gfn_t gfns[roundup_pow_of_two(ASYNC_PF_PER_VCPU)];
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index f88b72932c35..d19eb776f297 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -6407,6 +6407,7 @@ static void init_emulate_ctxt(struct kvm_vcpu *vcpu)
>
> kvm_x86_ops->get_cs_db_l_bits(vcpu, &cs_db, &cs_l);
>
> + /* last_retry_{eip,addr} are persistent and must not be init'd here. */
> ctxt->gpa_available = false;
> ctxt->eflags = kvm_get_rflags(vcpu);
> ctxt->tf = (ctxt->eflags & X86_EFLAGS_TF) != 0;
> @@ -6557,8 +6558,8 @@ static bool retry_instruction(struct x86_emulate_ctxt *ctxt,
> struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
> unsigned long last_retry_eip, last_retry_addr, gpa = cr2_or_gpa;
>
> - last_retry_eip = vcpu->arch.last_retry_eip;
> - last_retry_addr = vcpu->arch.last_retry_addr;
> + last_retry_eip = ctxt->last_retry_eip;
> + last_retry_addr = ctxt->last_retry_addr;
>
> /*
> * If the emulation is caused by #PF and it is non-page_table
> @@ -6573,7 +6574,7 @@ static bool retry_instruction(struct x86_emulate_ctxt *ctxt,
> * and the address again, we can break out of the potential infinite
> * loop.
> */
> - vcpu->arch.last_retry_eip = vcpu->arch.last_retry_addr = 0;
> + ctxt->last_retry_eip = ctxt->last_retry_addr = 0;
>
> if (!(emulation_type & EMULTYPE_ALLOW_RETRY_PF))
> return false;
> @@ -6588,8 +6589,8 @@ static bool retry_instruction(struct x86_emulate_ctxt *ctxt,
> if (ctxt->eip == last_retry_eip && last_retry_addr == cr2_or_gpa)
> return false;
>
> - vcpu->arch.last_retry_eip = ctxt->eip;
> - vcpu->arch.last_retry_addr = cr2_or_gpa;
> + ctxt->last_retry_eip = ctxt->eip;
> + ctxt->last_retry_addr = cr2_or_gpa;
>
> if (!vcpu->arch.mmu->direct_map)
> gpa = kvm_mmu_gva_to_gpa_write(vcpu, cr2_or_gpa, NULL);
>
next prev parent reply other threads:[~2020-02-19 8:13 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-18 23:03 [PATCH v2 0/3] KVM: x86: Minor emulator cleanup Sean Christopherson
2020-02-18 23:03 ` [PATCH v2 1/3] KVM: x86: Add EMULTYPE_PF when emulation is triggered by a page fault Sean Christopherson
2020-02-19 9:01 ` Xiaoyao Li
2020-02-20 20:11 ` Sean Christopherson
2020-02-21 2:59 ` Xiaoyao Li
2020-02-21 17:12 ` Paolo Bonzini
2020-02-18 23:03 ` [PATCH v2 2/3] KVM: x86: Move gpa_val and gpa_available into the emulator context Sean Christopherson
2020-02-18 23:03 ` [PATCH v2 3/3] KVM: x86: Move #PF retry tracking variables into emulation context Sean Christopherson
2020-02-19 8:13 ` Paolo Bonzini [this message]
2020-02-19 15:16 ` Sean Christopherson
2020-02-21 17:14 ` Paolo Bonzini
2020-02-21 18:28 ` Sean Christopherson
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