Messages in this thread | | | Subject | Re: [PATCH] kvm: Map PFN-type memory regions as writable (if possible) | From | Paolo Bonzini <> | Date | Wed, 17 Jan 2018 18:56:40 +0100 |
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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
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