From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933127AbXDAOnT (ORCPT ); Sun, 1 Apr 2007 10:43:19 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933227AbXDAOm5 (ORCPT ); Sun, 1 Apr 2007 10:42:57 -0400 Received: from il.qumranet.com ([82.166.9.18]:47551 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933219AbXDAOfo (ORCPT ); Sun, 1 Apr 2007 10:35:44 -0400 From: Avi Kivity To: kvm-devel@lists.sourceforge.net Cc: linux-kernel@vger.kernel.org, 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> X-Mailer: git-send-email 1.5.0.5 In-Reply-To: <117543813916-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> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@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