From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: [PATCH 08/10] KVM: Skip pio instruction when it is emulated, not executed Date: Sun, 2 Dec 2007 13:18:45 +0200 Message-ID: <11965943273087-git-send-email-avi@qumranet.com> References: <1196594327338-git-send-email-avi@qumranet.com> Cc: linux-kernel@vger.kernel.org, kvm-devel@lists.sourceforge.net, Avi Kivity To: stable@kernel.org Return-path: In-Reply-To: <1196594327338-git-send-email-avi@qumranet.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org If we defer updating rip until pio instructions are executed, we have a problem with reset: a pio reset updates rip, and when the instruction completes we skip the emulated instruction, pointing rip somewhere completely unrelated. Fix by updating rip when we see decode the instruction, not after emulation. Signed-off-by: Avi Kivity --- drivers/kvm/kvm_main.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index 504e81d..b58fdf3 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -1757,8 +1757,6 @@ static int complete_pio(struct kvm_vcpu *vcpu) io->count -= io->cur_count; io->cur_count = 0; - if (!io->count) - kvm_arch_ops->skip_emulated_instruction(vcpu); return 0; } @@ -1804,6 +1802,7 @@ int kvm_setup_pio(struct kvm_vcpu *vcpu, struct kvm_run *run, int in, pio_dev = vcpu_find_pio_dev(vcpu, port); if (!string) { + kvm_arch_ops->skip_emulated_instruction(vcpu); kvm_arch_ops->cache_regs(vcpu); memcpy(vcpu->pio_data, &vcpu->regs[VCPU_REGS_RAX], 4); kvm_arch_ops->decache_regs(vcpu); @@ -1850,6 +1849,9 @@ int kvm_setup_pio(struct kvm_vcpu *vcpu, struct kvm_run *run, int in, vcpu->run->io.count = now; vcpu->pio.cur_count = now; + if (now == count) + kvm_arch_ops->skip_emulated_instruction(vcpu); + for (i = 0; i < nr_pages; ++i) { spin_lock(&vcpu->kvm->lock); page = gva_to_page(vcpu, address + i * PAGE_SIZE); -- 1.5.3