From patchwork Thu Jun 18 10:56:00 2009 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andre Przywara X-Patchwork-Id: 31096 Received: from vger.kernel.org (vger.kernel.org [209.132.176.167]) by demeter.kernel.org (8.14.2/8.14.2) with ESMTP id n5IAqfRj018385 for ; Thu, 18 Jun 2009 10:52:41 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753298AbZFRKwg (ORCPT ); Thu, 18 Jun 2009 06:52:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753367AbZFRKwg (ORCPT ); Thu, 18 Jun 2009 06:52:36 -0400 Received: from va3ehsobe002.messaging.microsoft.com ([216.32.180.12]:9590 "EHLO VA3EHSOBE002.bigfish.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753063AbZFRKwf (ORCPT ); Thu, 18 Jun 2009 06:52:35 -0400 Received: from mail134-va3-R.bigfish.com (10.7.14.246) by VA3EHSOBE002.bigfish.com (10.7.40.22) with Microsoft SMTP Server id 8.1.340.0; Thu, 18 Jun 2009 10:52:37 +0000 Received: from mail134-va3 (localhost.localdomain [127.0.0.1]) by mail134-va3-R.bigfish.com (Postfix) with ESMTP id 00263850146; Thu, 18 Jun 2009 10:52:37 +0000 (UTC) X-SpamScore: -1 X-BigFish: VPS-1(zz4015Lzz1202hzzz32i17ch43j61h) X-Spam-TCS-SCL: 0:0 X-FB-SS: 5, Received: by mail134-va3 (MessageSwitch) id 1245322355249760_19120; Thu, 18 Jun 2009 10:52:35 +0000 (UCT) Received: from ausb3extmailp01.amd.com (unknown [163.181.251.8]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail134-va3.bigfish.com (Postfix) with ESMTP id 1A30816C004E; Thu, 18 Jun 2009 10:52:35 +0000 (UTC) Received: from ausb3twp01.amd.com ([163.181.250.37]) by ausb3extmailp01.amd.com (Switch-3.2.7/Switch-3.2.7) with ESMTP id n5IAqRAK001035; Thu, 18 Jun 2009 05:52:30 -0500 X-WSS-ID: 0KLFKVF-01-5LD-01 Received: from sausexbh1.amd.com (sausexbh1.amd.com [163.181.22.101]) by ausb3twp01.amd.com (Tumbleweed MailGate 3.5.1) with ESMTP id 2C16C1943C5; Thu, 18 Jun 2009 05:52:26 -0500 (CDT) Received: from SAUSEXMB3.amd.com ([163.181.22.202]) by sausexbh1.amd.com with Microsoft SMTPSVC(6.0.3790.3959); Thu, 18 Jun 2009 05:52:30 -0500 Received: from SDRSEXMB1.amd.com ([172.20.3.116]) by SAUSEXMB3.amd.com with Microsoft SMTPSVC(6.0.3790.3959); Thu, 18 Jun 2009 05:52:30 -0500 Received: from localhost.localdomain ([165.204.15.42]) by SDRSEXMB1.amd.com with Microsoft SMTPSVC(6.0.3790.3959); Thu, 18 Jun 2009 12:52:27 +0200 From: Andre Przywara To: avi@redhat.com CC: kvm@vger.kernel.org, Andre Przywara , Christoph Egger Subject: [PATCH 4/6 v2] add syscall emulation Date: Thu, 18 Jun 2009 12:56:00 +0200 Message-ID: <1245322562-3682-1-git-send-email-andre.przywara@amd.com> X-Mailer: git-send-email 1.6.1.3 In-Reply-To: <4A39FF5B.9080101@redhat.com> References: <4A39FF5B.9080101@redhat.com> X-OriginalArrivalTime: 18 Jun 2009 10:52:27.0648 (UTC) FILETIME=[DEDE4800:01C9F002] MIME-Version: 1.0 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Handle #UD intercept of the syscall instruction in 32bit compat mode on an Intel host. Setup the segment descriptors for CS and SS and the EIP/ESP registers according to the manual. Save the RIP and EFLAGS to the correct registers. Signed-off-by: Christoph Egger Signed-off-by: Andre Przywara --- arch/x86/kvm/x86_emulate.c | 82 +++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 81 insertions(+), 1 deletions(-) Avi, these are the new versions of patch 4-6/6. If you need delta patches, tell me. Thanks, Andre. diff --git a/arch/x86/kvm/x86_emulate.c b/arch/x86/kvm/x86_emulate.c index 328ccba..d0a51c4 100644 --- a/arch/x86/kvm/x86_emulate.c +++ b/arch/x86/kvm/x86_emulate.c @@ -1397,6 +1397,83 @@ void toggle_interruptibility(struct x86_emulate_ctxt *ctxt, u32 mask) ctxt->interruptibility = mask; } +static inline void +setup_syscalls_segments(struct x86_emulate_ctxt *ctxt, + struct kvm_segment *cs, struct kvm_segment *ss) +{ + memset(cs, 0, sizeof(struct kvm_segment)); + kvm_x86_ops->get_segment(ctxt->vcpu, cs, VCPU_SREG_CS); + memset(ss, 0, sizeof(struct kvm_segment)); + + cs->l = 0; /* will be adjusted later */ + cs->base = 0; /* flat segment */ + cs->g = 1; /* 4kb granularity */ + cs->limit = 0xffffffff; /* 4GB limit */ + cs->type = 0x0b; /* Read, Execute, Accessed */ + cs->s = 1; + cs->dpl = 0; /* will be adjusted later */ + cs->present = 1; + cs->db = 1; + + ss->unusable = 0; + ss->base = 0; /* flat segment */ + ss->limit = 0xffffffff; /* 4GB limit */ + ss->g = 1; /* 4kb granularity */ + ss->s = 1; + ss->type = 0x03; /* Read/Write, Accessed */ + ss->db = 1; /* 32bit stack segment */ + ss->dpl = 0; + ss->present = 1; +} + +static int +emulate_syscall(struct x86_emulate_ctxt *ctxt) +{ + struct decode_cache *c = &ctxt->decode; + struct kvm_segment cs, ss; + u64 msr_data; + + /* syscall is not available in real mode */ + if (c->lock_prefix || ctxt->mode == X86EMUL_MODE_REAL + || !(ctxt->vcpu->arch.cr0 & X86_CR0_PE)) + return -1; + + setup_syscalls_segments(ctxt, &cs, &ss); + + kvm_x86_ops->get_msr(ctxt->vcpu, MSR_STAR, &msr_data); + msr_data >>= 32; + cs.selector = (u16)(msr_data & 0xfffc); + ss.selector = (u16)(msr_data + 8); + + if (is_long_mode(ctxt->vcpu)) { + cs.db = 0; + cs.l = 1; + } + kvm_x86_ops->set_segment(ctxt->vcpu, &cs, VCPU_SREG_CS); + kvm_x86_ops->set_segment(ctxt->vcpu, &ss, VCPU_SREG_SS); + + c->regs[VCPU_REGS_RCX] = c->eip; + if (is_long_mode(ctxt->vcpu)) { + c->regs[VCPU_REGS_R11] = ctxt->eflags & ~EFLG_RF; + + kvm_x86_ops->get_msr(ctxt->vcpu, + ctxt->mode == X86EMUL_MODE_PROT64 ? + MSR_LSTAR : MSR_CSTAR, &msr_data); + c->eip = msr_data; + + kvm_x86_ops->get_msr(ctxt->vcpu, MSR_SYSCALL_MASK, &msr_data); + ctxt->eflags &= ~(msr_data | EFLG_RF); + } else { + /* legacy mode */ + kvm_x86_ops->get_msr(ctxt->vcpu, MSR_STAR, &msr_data); + c->eip = (u32)msr_data; + + ctxt->eflags &= ~(EFLG_VM | EFLG_IF | EFLG_RF); + } + + return 0; +} + int x86_emulate_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops) { @@ -1993,7 +2070,10 @@ twobyte_insn: } break; case 0x05: /* syscall */ - goto cannot_emulate; + if (emulate_syscall(ctxt) == -1) + goto cannot_emulate; + else + goto writeback; break; case 0x06: emulate_clts(ctxt->vcpu);