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 <[email protected]> Cc: Radim Krčmář <[email protected]> Cc: [email protected] Cc: [email protected] Signed-off-by: KarimAllah Ahmed <[email protected]> --- 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; -- 2.7.4
