From: Marcelo Tosatti <mtosatti@redhat.com>
To: Gleb Natapov <gleb@redhat.com>
Cc: kvm@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, avi@redhat.com, mingo@elte.hu,
a.p.zijlstra@chello.nl, tglx@linutronix.de, hpa@zytor.com,
riel@redhat.com, cl@linux-foundation.org
Subject: Re: [PATCH v4 09/12] Retry fault before vmentry
Date: Thu, 8 Jul 2010 13:17:11 -0300 [thread overview]
Message-ID: <20100708161711.GB13855@amt.cnet> (raw)
In-Reply-To: <1278433500-29884-10-git-send-email-gleb@redhat.com>
On Tue, Jul 06, 2010 at 07:24:57PM +0300, Gleb Natapov wrote:
> When page is swapped in it is mapped into guest memory only after guest
> tries to access it again and generate another fault. To save this fault
> we can map it immediately since we know that guest is going to access
> the page.
>
> Signed-off-by: Gleb Natapov <gleb@redhat.com>
> ---
> arch/x86/include/asm/kvm_host.h | 7 ++++++-
> arch/x86/kvm/mmu.c | 27 ++++++++++++++++++++-------
> arch/x86/kvm/paging_tmpl.h | 37 +++++++++++++++++++++++++++++++++----
> arch/x86/kvm/x86.c | 9 +++++++++
> virt/kvm/kvm_main.c | 2 ++
> 5 files changed, 70 insertions(+), 12 deletions(-)
>
> +static int FNAME(page_fault_other_cr3)(struct kvm_vcpu *vcpu, gpa_t cr3,
> + gva_t addr, u32 error_code)
> +{
> + int r = 0;
> + gpa_t curr_cr3 = vcpu->arch.cr3;
> +
> + if (curr_cr3 != cr3) {
> + /*
> + * We do page fault on behalf of a process that is sleeping
> + * because of async PF. PV guest takes reference to mm that cr3
> + * belongs too, so it has to be valid here.
> + */
> + kvm_set_cr3(vcpu, cr3);
> + if (kvm_mmu_reload(vcpu))
> + goto switch_cr3;
> + }
> +
> + r = FNAME(page_fault)(vcpu, addr, error_code, true);
KVM_REQ_MMU_SYNC request generated here must be processed before
switching to a different cr3 (otherwise vcpu_enter_guest will process it
with the wrong cr3 in place).
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next prev parent reply other threads:[~2010-07-08 16:53 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-07-06 16:24 [PATCH v4 00/12] KVM: Add host swap event notifications for PV guest Gleb Natapov
2010-07-06 16:24 ` [PATCH v4 01/12] Move kvm_smp_prepare_boot_cpu() from kvmclock.c to kvm.c Gleb Natapov
2010-07-07 16:17 ` Rik van Riel
2010-07-06 16:24 ` [PATCH v4 02/12] Add PV MSR to enable asynchronous page faults delivery Gleb Natapov
2010-07-07 18:13 ` Rik van Riel
2010-07-06 16:24 ` [PATCH v4 03/12] Add async PF initialization to PV guest Gleb Natapov
2010-07-07 15:41 ` Peter Zijlstra
2010-07-08 13:24 ` Gleb Natapov
2010-07-06 16:24 ` [PATCH v4 04/12] Provide special async page fault handler when async PF capability is detected Gleb Natapov
2010-07-07 22:38 ` Rik van Riel
2010-07-06 16:24 ` [PATCH v4 05/12] Export __get_user_pages_fast Gleb Natapov
2010-07-07 22:45 ` Rik van Riel
2010-07-06 16:24 ` [PATCH v4 06/12] Add get_user_pages() variant that fails if major fault is required Gleb Natapov
2010-07-06 16:24 ` [PATCH v4 07/12] Maintain memslot version number Gleb Natapov
2010-07-08 0:19 ` Rik van Riel
2010-07-06 16:24 ` [PATCH v4 08/12] Inject asynchronous page fault into a guest if page is swapped out Gleb Natapov
2010-07-08 4:09 ` Rik van Riel
2010-07-08 15:59 ` Marcelo Tosatti
2010-07-08 18:05 ` Gleb Natapov
2010-07-08 18:09 ` Peter Zijlstra
2010-07-08 18:10 ` Peter Zijlstra
2010-07-09 15:50 ` Gleb Natapov
2010-07-06 16:24 ` [PATCH v4 09/12] Retry fault before vmentry Gleb Natapov
2010-07-08 4:21 ` Rik van Riel
2010-07-08 16:17 ` Marcelo Tosatti [this message]
2010-07-06 16:24 ` [PATCH v4 10/12] Handle async PF in non preemptable context Gleb Natapov
2010-07-08 4:22 ` Rik van Riel
2010-07-06 16:24 ` [PATCH v4 11/12] Let host know whether the guest can handle async PF in non-userspace context Gleb Natapov
2010-07-08 4:28 ` Rik van Riel
2010-07-08 13:35 ` Gleb Natapov
2010-07-06 16:25 ` [PATCH v4 12/12] Send async PF when guest is not in userspace too Gleb Natapov
2010-07-08 4:29 ` Rik van Riel
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