From c86813393f8b8f9f738ab57d9837858ed850df4b Mon Sep 17 00:00:00 2001 From: Anthony Liguori Date: Mon, 30 Apr 2007 09:48:11 +0300 Subject: [PATCH] KVM: SVM: Allow direct guest access to PC debug port The PC debug port is used for IO delay and does not require emulation. Signed-off-by: Anthony Liguori Signed-off-by: Avi Kivity --- drivers/kvm/svm.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c index fa17d6d4f0cb..6cd6a50a0340 100644 --- a/drivers/kvm/svm.c +++ b/drivers/kvm/svm.c @@ -378,7 +378,7 @@ static __init int svm_hardware_setup(void) int cpu; struct page *iopm_pages; struct page *msrpm_pages; - void *msrpm_va; + void *iopm_va, *msrpm_va; int r; kvm_emulator_want_group7_invlpg(); @@ -387,8 +387,10 @@ static __init int svm_hardware_setup(void) if (!iopm_pages) return -ENOMEM; - memset(page_address(iopm_pages), 0xff, - PAGE_SIZE * (1 << IOPM_ALLOC_ORDER)); + + 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; -- 2.30.2