From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eugene Korenevsky Subject: [PATCH] kvm: x86: vmx: add checks on guest RIP Date: Sat, 29 Nov 2014 18:27:26 +0300 Message-ID: <20141129152726.GA25370@gnote> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii To: Paolo Bonzini , kvm@vger.kernel.org Return-path: Received: from mail-lb0-f172.google.com ([209.85.217.172]:35446 "EHLO mail-lb0-f172.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751033AbaK2P0O (ORCPT ); Sat, 29 Nov 2014 10:26:14 -0500 Received: by mail-lb0-f172.google.com with SMTP id u10so6736472lbd.31 for ; Sat, 29 Nov 2014 07:26:12 -0800 (PST) Content-Disposition: inline Sender: kvm-owner@vger.kernel.org List-ID: Signed-off-by: Eugene Korenevsky --- Notes: This patch adds checks on Guest RIP specified in Intel Software Developer Manual. The following checks are performed on processors that support Intel 64 architecture: - Bits 63:32 must be 0 if the "IA-32e mode guest" VM-entry control is 0 or if the L bit (bit 13) in the access-rights field for CS is 0. - If the processor supports N < 64 linear-address bits, bits 63:N must be identical if the "IA-32e mode guest" VM-entry control is 1 and the L bit in the access-rights field for CS is 1. (No check applies if the processor supports 64 linear-address bits.) arch/x86/kvm/vmx.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 6a951d8..e2da83b 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -3828,6 +3828,28 @@ static bool cs_ss_rpl_check(struct kvm_vcpu *vcpu) (ss.selector & SELECTOR_RPL_MASK)); } +#ifdef CONFIG_X86_64 +static bool rip_valid(struct kvm_vcpu *vcpu) +{ + unsigned long rip; + struct kvm_segment cs; + bool longmode; + + /* RIP must be canonical in long mode + * Bits 63:32 of RIP must be zero in other processor modes */ + longmode = false; + if (vm_entry_controls_get(to_vmx(vcpu)) & VM_ENTRY_IA32E_MODE) { + vmx_get_segment(vcpu, &cs, VCPU_SREG_CS); + longmode = (cs.l != 0); + } + rip = kvm_register_read(vcpu, VCPU_REGS_RIP); + if (longmode) + return !is_noncanonical_address(rip); + else + return (rip >> 32) == 0; +} +#endif + /* * Check if guest state is valid. Returns true if valid, false if * not. @@ -3873,8 +3895,11 @@ static bool guest_state_valid(struct kvm_vcpu *vcpu) if (!ldtr_valid(vcpu)) return false; } +#ifdef CONFIG_X86_64 + if (!rip_valid(vcpu)) + return false; +#endif /* TODO: - * - Add checks on RIP * - Add checks on RFLAGS */ -- 2.0.4