From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: [PATCH 23/41] KVM: Workaround vmx inability to virtualize the reset state Date: Sun, 1 Apr 2007 17:35:20 +0300 Message-ID: <1175438139530-git-send-email-avi@qumranet.com> References: <1175438138288-git-send-email-avi@qumranet.com> <11754381381990-git-send-email-avi@qumranet.com> <11754381384009-git-send-email-avi@qumranet.com> <1175438138805-git-send-email-avi@qumranet.com> <11754381382515-git-send-email-avi@qumranet.com> <11754381383730-git-send-email-avi@qumranet.com> <11754381383144-git-send-email-avi@qumranet.com> <11754381381597-git-send-email-avi@qumranet.com> <1175438139242-git-send-email-avi@qumranet.com> <1175438139494-git-send-email-avi@qumranet.com> <11754381392046-git-send-email-avi@qumranet.com> <1175438139795-git-send-email-avi@qumranet.com> <1175438139430-git-send-email-avi@qumranet.com> <11754381393496-git-send-email-avi@qumranet.com> <11754381391514-git-send-email-avi@qumranet.com> <11754381392382-git-send-email-avi@qumranet.com> <11754381392358-git-send-email-avi@qumranet.com> <1175438139872-git-send-email-avi@qumranet.com> <11754381392921-git-send-email-avi@qumranet.com> <117543813978-git-send-email-avi@qumranet.com> <117543 81393061-git-send-email-avi@qumranet.com> <11754381392186-git-send-email-avi@qumranet.com> <117543813916-git-send-email-avi@qumranet.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Return-path: In-Reply-To: <117543813916-git-send-email-avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org The reset state has cs.selector == 0xf000 and cs.base == 0xffff0000, which aren't compatible with vm86 mode, which is used for real mode virtualization. When we create a vcpu, we set cs.base to 0xf0000, but if we get there by way of a reset, the values are inconsistent and vmx refuses to enter guest mode. Workaround by detecting the state and munging it appropriately. Signed-off-by: Avi Kivity --- drivers/kvm/vmx.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c index 0d9bf0b..aa7e2ba 100644 --- a/drivers/kvm/vmx.c +++ b/drivers/kvm/vmx.c @@ -712,6 +712,8 @@ static void enter_rmode(struct kvm_vcpu *vcpu) vmcs_write32(GUEST_CS_AR_BYTES, 0xf3); vmcs_write32(GUEST_CS_LIMIT, 0xffff); + if (vmcs_readl(GUEST_CS_BASE) == 0xffff0000) + vmcs_writel(GUEST_CS_BASE, 0xf0000); vmcs_write16(GUEST_CS_SELECTOR, vmcs_readl(GUEST_CS_BASE) >> 4); fix_rmode_seg(VCPU_SREG_ES, &vcpu->rmode.es); -- 1.5.0.5 ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV