From: Avi Kivity <avi@redhat.com>
To: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>,
LKML <linux-kernel@vger.kernel.org>, KVM <kvm@vger.kernel.org>
Subject: Re: [PATCH v3 03/11] KVM: x86: retry non-page-table writing instruction
Date: Tue, 13 Sep 2011 13:47:43 +0300 [thread overview]
Message-ID: <4E6F34CF.1060302@redhat.com> (raw)
In-Reply-To: <4E5C4C5C.8030602@cn.fujitsu.com>
On 08/30/2011 05:35 AM, Xiao Guangrong wrote:
> If the emulation is caused by #PF and it is non-page_table writing instruction,
> it means the VM-EXIT is caused by shadow page protected, we can zap the shadow
> page and retry this instruction directly
>
> The idea is from Avi
>
>
> int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len);
> +bool page_table_writing_insn(struct x86_emulate_ctxt *ctxt);
Please use the usual x86_ prefix used in the emulator interface.
> @@ -3720,10 +3721,18 @@ void __kvm_mmu_free_some_pages(struct kvm_vcpu *vcpu)
> kvm_mmu_commit_zap_page(vcpu->kvm,&invalid_list);
> }
>
> +static bool is_mmio_page_fault(struct kvm_vcpu *vcpu, gva_t addr)
> +{
> + if (vcpu->arch.mmu.direct_map || mmu_is_nested(vcpu))
> + return vcpu_match_mmio_gpa(vcpu, addr);
> +
> + return vcpu_match_mmio_gva(vcpu, addr);
> +}
> +
> int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code,
> void *insn, int insn_len)
> {
> - int r;
> + int r, emulation_type = EMULTYPE_RETRY;
> enum emulation_result er;
>
> r = vcpu->arch.mmu.page_fault(vcpu, cr2, error_code, false);
> @@ -3735,7 +3744,10 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t cr2, u32 error_code,
> goto out;
> }
>
> - er = x86_emulate_instruction(vcpu, cr2, 0, insn, insn_len);
> + if (is_mmio_page_fault(vcpu, cr2))
> + emulation_type = 0;
> +
> + er = x86_emulate_instruction(vcpu, cr2, emulation_type, insn, insn_len);
>
> switch (er) {
> case EMULATE_DONE:
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 6b37f18..1afe59e 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -4814,6 +4814,50 @@ static bool reexecute_instruction(struct kvm_vcpu *vcpu, gva_t gva)
> return false;
> }
>
> +static bool retry_instruction(struct x86_emulate_ctxt *ctxt,
> + unsigned long cr2, int emulation_type)
> +{
> + if (!vcpu->arch.mmu.direct_map&& !mmu_is_nested(vcpu))
> + gpa = kvm_mmu_gva_to_gpa_write(vcpu, cr2, NULL);
If mmu_is_nested() cr2 is an ngpa, we have to translate it to a gpa, no?
btw, I don't see mmu.direct_map initialized for nested npt?
> +
> + kvm_mmu_unprotect_page(vcpu->kvm, gpa>> PAGE_SHIFT);
> +
> + return true;
> +}
> +
> int x86_emulate_instruction(struct kvm_vcpu *vcpu,
> unsigned long cr2,
> int emulation_type,
> @@ -4855,6 +4899,9 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu,
> return EMULATE_DONE;
> }
>
> + if (retry_instruction(ctxt, cr2, emulation_type))
> + return EMULATE_DONE;
> +
> /* this is needed for vmware backdoor interface to work since it
> changes registers values during IO operation */
> if (vcpu->arch.emulate_regs_need_sync_from_vcpu) {
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2011-09-13 10:47 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-08-30 2:34 [PATCH v3 01/11] KVM: MMU: avoid pte_list_desc running out in kvm_mmu_pte_write Xiao Guangrong
2011-08-30 2:34 ` [PATCH v3 02/11] KVM: x86: tag the instructions which are used to write page table Xiao Guangrong
2011-08-30 2:35 ` [PATCH v3 03/11] KVM: x86: retry non-page-table writing instruction Xiao Guangrong
2011-09-13 10:47 ` Avi Kivity [this message]
2011-09-13 18:24 ` Xiao Guangrong
2011-09-14 9:53 ` Avi Kivity
2011-09-14 10:19 ` Xiao Guangrong
2011-09-15 4:56 ` Xiao Guangrong
2011-08-30 2:35 ` [PATCH v3 04/11] KVM: x86: cleanup port-in/port-out emulated Xiao Guangrong
2011-08-30 2:35 ` [PATCH v3 05/11] KVM: MMU: do not mark accessed bit on pte write path Xiao Guangrong
2011-09-13 10:53 ` Avi Kivity
2011-09-13 18:29 ` Xiao Guangrong
2011-09-14 9:55 ` Avi Kivity
2011-09-15 13:11 ` Marcelo Tosatti
2011-08-30 2:36 ` [PATCH v3 06/11] KVM: MMU: cleanup FNAME(invlpg) Xiao Guangrong
2011-09-13 11:00 ` Avi Kivity
2011-09-13 18:31 ` Xiao Guangrong
2011-09-14 9:57 ` Avi Kivity
2011-08-30 2:36 ` [PATCH v3 07/11] KVM: MMU: fast prefetch spte on invlpg path Xiao Guangrong
2011-08-30 2:37 ` [PATCH v3 08/11] KVM: MMU: remove unnecessary kvm_mmu_free_some_pages Xiao Guangrong
2011-08-30 2:37 ` [PATCH v3 09/11] KVM: MMU: split kvm_mmu_pte_write function Xiao Guangrong
2011-08-30 2:37 ` [PATCH v3 10/11] KVM: MMU: fix detecting misaligned accessed Xiao Guangrong
2011-08-30 2:38 ` [PATCH v3 11/11] KVM: MMU: improve write flooding detected Xiao Guangrong
2011-09-13 11:07 ` Avi Kivity
2011-09-13 19:19 ` Xiao Guangrong
2011-09-14 9:59 ` Avi Kivity
2011-09-13 9:51 ` [PATCH v3 01/11] KVM: MMU: avoid pte_list_desc running out in kvm_mmu_pte_write Avi Kivity
2011-09-13 10:24 ` Xiao Guangrong
2011-09-13 10:50 ` Avi Kivity
2011-09-13 19:31 ` Xiao Guangrong
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