| Message ID | 1516209965-18614-1-git-send-email-karahmed@amazon.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 17/01/2018 18:26, KarimAllah Ahmed wrote: > For EPT-violations that are triggered by a read, the pages are also mapped with > write permissions (if their memory region is also writable). That would avoid > getting yet another fault on the same page when a write occurs. > > This optimization only happens when you have a "struct page" backing the memory > region. So also enable it for memory regions that do not have a "struct page". > > Cc: Paolo Bonzini <pbonzini@redhat.com> > Cc: Radim Krčmář <rkrcmar@redhat.com> > Cc: kvm@vger.kernel.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> > --- > virt/kvm/kvm_main.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c > index 97da45e..0efb089 100644 > --- a/virt/kvm/kvm_main.c > +++ b/virt/kvm/kvm_main.c > @@ -1534,6 +1534,8 @@ static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, > goto retry; > if (r < 0) > pfn = KVM_PFN_ERR_FAULT; > + if (writable) > + *writable = true; > } else { > if (async && vma_is_valid(vma, write_fault)) > *async = true; > Looks good, but it should be in hva_to_pfn_remapped. Paolo
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 97da45e..0efb089 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1534,6 +1534,8 @@ static kvm_pfn_t hva_to_pfn(unsigned long addr, bool atomic, bool *async, goto retry; if (r < 0) pfn = KVM_PFN_ERR_FAULT; + if (writable) + *writable = true; } else { if (async && vma_is_valid(vma, write_fault)) *async = true;
For EPT-violations that are triggered by a read, the pages are also mapped with write permissions (if their memory region is also writable). That would avoid getting yet another fault on the same page when a write occurs. This optimization only happens when you have a "struct page" backing the memory region. So also enable it for memory regions that do not have a "struct page". Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: kvm@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: KarimAllah Ahmed <karahmed@amazon.de> --- virt/kvm/kvm_main.c | 2 ++ 1 file changed, 2 insertions(+)