From: Gleb Natapov <gleb@redhat.com>
To: Sanjay Lal <sanjayl@kymasys.com>
Cc: kvm@vger.kernel.org, linux-mips@linux-mips.org
Subject: Re: [PATCH v2 07/18] KVM/MIPS32: MMU/TLB operations for the Guest.
Date: Sat, 16 Feb 2013 18:21:45 +0200 [thread overview]
Message-ID: <20130216162145.GA15961@redhat.com> (raw)
In-Reply-To: <15B0FF73-7030-4861-B7BD-834F12CEF5B1@kymasys.com>
On Sat, Feb 16, 2013 at 10:57:22AM -0500, Sanjay Lal wrote:
>
> On Feb 15, 2013, at 1:41 PM, Gleb Natapov wrote:
>
> > On Fri, Feb 15, 2013 at 01:19:29PM -0500, Sanjay Lal wrote:
> >>
> >> On Feb 6, 2013, at 7:08 AM, Gleb Natapov wrote:
> >>
> >>>>
> >>>> +static void kvm_mips_map_page(struct kvm *kvm, gfn_t gfn)
> >>>> +{
> >>>> + pfn_t pfn;
> >>>> +
> >>>> + if (kvm->arch.guest_pmap[gfn] != KVM_INVALID_PAGE)
> >>>> + return;
> >>>> +
> >>>> + pfn =kvm_mips_gfn_to_pfn(kvm, gfn);
> >>> This call should be in srcu read section since it access memory slots which
> >>> are srcu protected. You should test with RCU debug enabled.
> >>
> >> kvm_mips_gfn_to_pfn just maps to gfn_to_pfn. I don't see an instance where gfn_to_pfn is in a scru read section?
> >>
> > Where are you looking? On x86 if vcpu is not in a guest mode it is in
> > srcu read section. The lock is taken immediately after exit and released
> > before entry. This is because x86 access memory slots a lot. Other
> > arches, that do not access memory slots as much, take the lock around
> > each individual access. As far as I see this is the only place in MIPS
> > kvm where this is needed.
>
> Ah I see what you mean. I'll wrap the access in a scru read section.
>
Thanks.
I think there is userspace triggerable panic() in kvm_mips_map_page().
See my original reply. Just making sure you haven't missed it :)
--
Gleb.
next prev parent reply other threads:[~2013-02-16 16:21 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-11-22 2:33 [PATCH v2 00/18] KVM for MIPS32 Processors Sanjay Lal
2012-11-22 2:33 ` [PATCH v2 01/18] KVM/MIPS32: Infrastructure/build files Sanjay Lal
2012-11-22 2:34 ` [PATCH v2 02/18] KVM/MIPS32: Arch specific KVM data structures Sanjay Lal
2012-12-26 13:14 ` Gleb Natapov
2013-01-24 13:22 ` Ralf Baechle
2013-01-31 20:12 ` David Daney
2013-02-06 13:11 ` Gleb Natapov
2012-11-22 2:34 ` [PATCH v2 03/18] KVM/MIPS32: Entry point for trampolining to the guest and trap handlers Sanjay Lal
2012-11-22 2:34 ` [PATCH v2 04/18] KVM/MIPS32: MIPS arch specific APIs for KVM Sanjay Lal
2012-11-22 2:34 ` [PATCH v2 05/18] KVM/MIPS32: KVM Guest kernel support Sanjay Lal
2012-11-22 2:34 ` [PATCH v2 06/18] KVM/MIPS32: Privileged instruction/target branch emulation Sanjay Lal
2012-11-22 2:34 ` [PATCH v2 07/18] KVM/MIPS32: MMU/TLB operations for the Guest Sanjay Lal
2013-02-06 12:08 ` Gleb Natapov
2013-02-15 18:19 ` Sanjay Lal
2013-02-15 18:41 ` Gleb Natapov
2013-02-16 15:57 ` Sanjay Lal
2013-02-16 16:21 ` Gleb Natapov [this message]
2012-11-22 2:34 ` [PATCH v2 08/18] KVM/MIPS32: Release notes and KVM module Makefile Sanjay Lal
2012-11-22 2:34 ` [PATCH v2 09/18] KVM/MIPS32: COP0 accesses profiling Sanjay Lal
2012-11-22 11:45 ` Sergei Shtylyov
2013-02-06 13:17 ` Gleb Natapov
2013-02-15 18:22 ` Sanjay Lal
2012-11-22 2:34 ` [PATCH v2 10/18] KVM/MIPS32: Guest interrupt delivery Sanjay Lal
2012-11-22 2:34 ` [PATCH v2 11/18] KVM/MIPS32: Routines to handle specific traps/exceptions while executing the guest Sanjay Lal
2013-02-06 13:20 ` Gleb Natapov
2013-02-15 16:10 ` Sanjay Lal
2013-02-18 9:44 ` Gleb Natapov
2013-02-19 2:31 ` Sanjay Lal
2012-11-22 2:34 ` [PATCH v2 12/18] MIPS: Export routines needed by the KVM module Sanjay Lal
2012-11-22 2:34 ` [PATCH v2 13/18] MIPS: If KVM is enabled then use the KVM specific routine to flush the TLBs on a ASID wrap Sanjay Lal
2012-11-22 2:34 ` [PATCH v2 14/18] MIPS: ASM offsets for VCPU arch specific fields Sanjay Lal
2012-11-22 2:34 ` [PATCH v2 15/18] MIPS: Pull in MIPS fix: fix endless loop when processing signals for kernel tasks Sanjay Lal
2013-01-24 13:07 ` Ralf Baechle
2012-11-22 2:34 ` [PATCH v2 16/18] MIPS: Export symbols used by KVM/MIPS module Sanjay Lal
2012-11-22 2:34 ` [PATCH v2 17/18] KVM/MIPS32: Do not call vcpu_load when injecting interrupts Sanjay Lal
2012-11-22 2:34 ` [PATCH v2 18/18] KVM/MIPS32: Binary patching of select privileged instructions Sanjay Lal
2012-11-26 18:53 ` [PATCH v2 00/18] KVM for MIPS32 Processors David Daney
2012-11-27 19:35 ` Sanjay Lal
2013-01-24 15:05 ` Ralf Baechle
2013-01-24 15:59 ` Sanjay Lal
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