| Message ID | 1378376958-27252-3-git-send-email-xiaoguangrong@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Sep 05, 2013 at 06:29:05PM +0800, Xiao Guangrong wrote: > Using sp->role.level instead of @level since @level is not got from the > page table hierarchy > > There is no issue in current code since the fast page fault currently only > fixes the fault caused by dirty-log that is always on the last level > (level = 1) > > This patch makes the code more readable and avoids potential issue in the > further development > > Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> > --- > arch/x86/kvm/mmu.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index 7714fd8..869f1db 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -2804,9 +2804,9 @@ static bool page_fault_can_be_fast(u32 error_code) > } > > static bool > -fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 spte) > +fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, > + u64 *sptep, u64 spte) > { > - struct kvm_mmu_page *sp = page_header(__pa(sptep)); > gfn_t gfn; > > WARN_ON(!sp->role.direct); > @@ -2832,6 +2832,7 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gva_t gva, int level, > u32 error_code) > { > struct kvm_shadow_walk_iterator iterator; > + struct kvm_mmu_page *sp; > bool ret = false; > u64 spte = 0ull; > > @@ -2852,7 +2853,8 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gva_t gva, int level, > goto exit; > } > > - if (!is_last_spte(spte, level)) > + sp = page_header(__pa(iterator.sptep)); > + if (!is_last_spte(spte, sp->role.level)) > goto exit; > > /* > @@ -2878,7 +2880,7 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gva_t gva, int level, > * the gfn is not stable for indirect shadow page. > * See Documentation/virtual/kvm/locking.txt to get more detail. > */ > - ret = fast_pf_fix_direct_spte(vcpu, iterator.sptep, spte); > + ret = fast_pf_fix_direct_spte(vcpu, sp, iterator.sptep, spte); > exit: > trace_fast_page_fault(vcpu, gva, error_code, iterator.sptep, > spte, ret); > -- > 1.8.1.4 Unrelated to this patch: If vcpu->mode = OUTSIDE_GUEST_MODE, no IPI is sent by kvm_flush_remote_tlbs. So how is this supposed to work again? /* * Wait for all vcpus to exit guest mode and/or lockless shadow * page table walks. */ kvm_flush_remote_tlbs(kvm); Patch looks fine. -- 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
On Oct 1, 2013, at 5:23 AM, Marcelo Tosatti <mtosatti@redhat.com> wrote: >> > > Unrelated to this patch: > > If vcpu->mode = OUTSIDE_GUEST_MODE, no IPI is sent > by kvm_flush_remote_tlbs. Yes. > > So how is this supposed to work again? > > /* > * Wait for all vcpus to exit guest mode and/or lockless shadow > * page table walks. > */ On the lockless walking path, we change the vcpu->mode to READING_SHADOW_PAGE_TABLES, so that IPI is needed. Or i missed your question? > kvm_flush_remote_tlbs(kvm); > > Patch looks fine. Thank you, Marcelo! -- 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
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 7714fd8..869f1db 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2804,9 +2804,9 @@ static bool page_fault_can_be_fast(u32 error_code) } static bool -fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, u64 *sptep, u64 spte) +fast_pf_fix_direct_spte(struct kvm_vcpu *vcpu, struct kvm_mmu_page *sp, + u64 *sptep, u64 spte) { - struct kvm_mmu_page *sp = page_header(__pa(sptep)); gfn_t gfn; WARN_ON(!sp->role.direct); @@ -2832,6 +2832,7 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gva_t gva, int level, u32 error_code) { struct kvm_shadow_walk_iterator iterator; + struct kvm_mmu_page *sp; bool ret = false; u64 spte = 0ull; @@ -2852,7 +2853,8 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gva_t gva, int level, goto exit; } - if (!is_last_spte(spte, level)) + sp = page_header(__pa(iterator.sptep)); + if (!is_last_spte(spte, sp->role.level)) goto exit; /* @@ -2878,7 +2880,7 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gva_t gva, int level, * the gfn is not stable for indirect shadow page. * See Documentation/virtual/kvm/locking.txt to get more detail. */ - ret = fast_pf_fix_direct_spte(vcpu, iterator.sptep, spte); + ret = fast_pf_fix_direct_spte(vcpu, sp, iterator.sptep, spte); exit: trace_fast_page_fault(vcpu, gva, error_code, iterator.sptep, spte, ret);
Using sp->role.level instead of @level since @level is not got from the page table hierarchy There is no issue in current code since the fast page fault currently only fixes the fault caused by dirty-log that is always on the last level (level = 1) This patch makes the code more readable and avoids potential issue in the further development Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> --- arch/x86/kvm/mmu.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)