From: Alexander Graf <agraf@suse.de>
To: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Avi Kivity <avi@redhat.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"joerg.roedel@amd.com" <joerg.roedel@amd.com>
Subject: Re: [PATCH] KVM: MMU: Segregate mmu pages created with different cr4.pge settings
Date: Thu, 8 Jan 2009 20:53:21 +0100 [thread overview]
Message-ID: <585C48B8-973C-4792-9122-F0ED36C05754@suse.de> (raw)
In-Reply-To: <20090107134606.GA4977@amt.cnet>
Sorry for the late reply - I wanted to know who kvm hangs in the host
kernel context :)
On 07.01.2009, at 14:46, Marcelo Tosatti <mtosatti@redhat.com> wrote:
> On Wed, Jan 07, 2009 at 01:32:41PM +0200, Avi Kivity wrote:
>> Marcelo Tosatti wrote:
>>> Let me shoot at one direction: a shadow page with PGE bit in either
>>> state is created. Later that shadow page is nuked (via mmu
>>> notifiers,
>>> for example).
>>
>> I doubt that mmu notifiers were invoked in this case (the bug would
>> be
>> very rare); in any case we flush the tlb.
>
> This comment is worrying
>
> /*
> * FIXME: Tis shouldn't be necessary here, but there is a flush
> * missing in the MMU code. Until we find this bug, flush the
> * complete TLB here on an NPF
> */
> if (npt_enabled)
> svm_flush_tlb(&svm->vcpu);
>
This is in, because netbench in an npt-guest failed after a few
minutes (see Alex W's bug report) and this appeard to fix it.
> Alexander, you might want to try this patch, -ENONPT here (and
> revert the previous
> one).
Eh, what?
> I have no clue, what else could be causing this?
>
> diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
> index 10bdb2a..bf68e5b 100644
> --- a/arch/x86/kvm/mmu.c
> +++ b/arch/x86/kvm/mmu.c
> @@ -33,6 +33,7 @@
> #include <asm/cmpxchg.h>
> #include <asm/io.h>
> #include <asm/vmx.h>
> +#include <asm/tlbflush.h>
>
> /*
> * When setting this variable to true it enables Two-Dimensional-
> Paging
> @@ -1850,6 +1851,11 @@ static int __direct_map(struct kvm_vcpu
> *vcpu, gpa_t v, int write,
>
> if (*iterator.sptep == shadow_trap_nonpresent_pte) {
> pseudo_gfn = (iterator.addr & PT64_DIR_BASE_ADDR_MASK) >>
> PAGE_SHIFT;
> +
> + kvm_flush_remote_tlbs(vcpu->kvm);
> + kvm_mmu_flush_tlb(vcpu);
> + __flush_tlb();
> +
> sp = kvm_mmu_get_page(vcpu, pseudo_gfn, iterator.addr,
> iterator.level - 1,
> 1, ACC_ALL, iterator.sptep);
> --
> To unsubscribe from this list: send the line "unsubscribe kvm" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2009-01-08 19:53 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20081221184146.8E00B250012@cleopatra.tlv.redhat.com>
2009-01-05 14:56 ` [PATCH] KVM: MMU: Segregate mmu pages created with different cr4.pge settings Alexander Graf
2009-01-06 10:41 ` Avi Kivity
2009-01-06 14:11 ` Marcelo Tosatti
2009-01-06 14:29 ` Avi Kivity
2009-01-06 15:06 ` Marcelo Tosatti
2009-01-06 16:43 ` Marcelo Tosatti
2009-01-07 6:49 ` Alexander Graf
2009-01-07 10:19 ` Avi Kivity
2009-01-07 10:43 ` Marcelo Tosatti
2009-01-07 11:32 ` Avi Kivity
2009-01-07 13:46 ` Marcelo Tosatti
2009-01-08 19:53 ` Alexander Graf [this message]
2009-01-09 0:36 ` Marcelo Tosatti
2009-01-09 10:43 ` Alexander Graf
2009-01-11 9:12 Marcelo Tosatti
2009-01-11 9:20 ` Avi Kivity
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