kvm: Map PFN-type memory regions as writable (if possible)
authorKarimAllah Ahmed <karahmed@amazon.de>
Wed, 17 Jan 2018 18:18:56 +0000 (19:18 +0100)
committerRadim Krčmář <rkrcmar@redhat.com>
Wed, 31 Jan 2018 17:25:33 +0000 (18:25 +0100)
commita340b3e229b24a56f1c7f5826b15a3af0f4b13e5
treea49fd00bcff34d0d2c7b5235f14da0315ead715e
parente53175395d7e12d8474707271bc02a2814279843
kvm: Map PFN-type memory regions as writable (if possible)

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>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
virt/kvm/kvm_main.c