From a6ddabcdf09bf394de04ca5c772129cb8fc6e179 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Mon, 11 May 2009 14:21:10 +0300 Subject: [PATCH] KVM: SVM: Remove port 80 passthrough MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit commit 99f85a28a78e96d28907fe036e1671a218fee597 upstream. KVM optimizes guest port 80 accesses by passthing them through to the host. Some AMD machines die on port 80 writes, allowing the guest to hard-lock the host. Remove the port passthrough to avoid the problem. Reported-by: Piotr Jaroszyński Tested-by: Piotr Jaroszyński Signed-off-by: Avi Kivity Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/svm.c | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index da568212966a..dd8eeeae5979 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -411,7 +411,6 @@ static __init int svm_hardware_setup(void) iopm_va = page_address(iopm_pages); memset(iopm_va, 0xff, PAGE_SIZE * (1 << IOPM_ALLOC_ORDER)); - clear_bit(0x80, iopm_va); /* allow direct access to PC debug port */ iopm_base = page_to_pfn(iopm_pages) << PAGE_SHIFT; if (boot_cpu_has(X86_FEATURE_NX)) -- 2.39.5