This is a note to let you know that I've just added the patch titled KVM: use slowpath for cross page cached accesses to the 3.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kvm-use-slowpath-for-cross-page-cached-accesses.patch and it can be found in the queue-3.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From ca3f0874723fad81d0c701b63ae3a17a408d5f25 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= <rkrcmar@xxxxxxxxxx> Date: Wed, 8 Apr 2015 14:16:48 +0200 Subject: KVM: use slowpath for cross page cached accesses MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: =?UTF-8?q?Radim=20Kr=C4=8Dm=C3=A1=C5=99?= <rkrcmar@xxxxxxxxxx> commit ca3f0874723fad81d0c701b63ae3a17a408d5f25 upstream. kvm_write_guest_cached() does not mark all written pages as dirty and code comments in kvm_gfn_to_hva_cache_init() talk about NULL memslot with cross page accesses. Fix all the easy way. The check is '<= 1' to have the same result for 'len = 0' cache anywhere in the page. (nr_pages_needed is 0 on page boundary.) Fixes: 8f964525a121 ("KVM: Allow cross page reads and writes from cached translations.") Signed-off-by: Radim Krčmář <rkrcmar@xxxxxxxxxx> Message-Id: <20150408121648.GA3519@xxxxxxxxxxxxxxxxxxxxx> Reviewed-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxxxxxx> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- virt/kvm/kvm_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1608,8 +1608,8 @@ int kvm_gfn_to_hva_cache_init(struct kvm ghc->generation = slots->generation; ghc->len = len; ghc->memslot = gfn_to_memslot(kvm, start_gfn); - ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn, &nr_pages_avail); - if (!kvm_is_error_hva(ghc->hva) && nr_pages_avail >= nr_pages_needed) { + ghc->hva = gfn_to_hva_many(ghc->memslot, start_gfn, NULL); + if (!kvm_is_error_hva(ghc->hva) && nr_pages_needed <= 1) { ghc->hva += offset; } else { /* Patches currently in stable-queue which might be from rkrcmar@xxxxxxxxxx are queue-3.19/kvm-use-slowpath-for-cross-page-cached-accesses.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html