linux-kernel - [PATCH v3 11/13] KVM: x86: SVM: use smram structs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed,  3 Aug 2022 18:50:09 +0300
From:   Maxim Levitsky <mlevitsk@...hat.com>
To:     kvm@...r.kernel.org
Cc:     Borislav Petkov <bp@...en8.de>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        linux-kernel@...r.kernel.org, Wanpeng Li <wanpengli@...cent.com>,
        Maxim Levitsky <mlevitsk@...hat.com>,
        Ingo Molnar <mingo@...hat.com>,
        Sean Christopherson <seanjc@...gle.com>, x86@...nel.org,
        Jim Mattson <jmattson@...gle.com>,
        Kees Cook <keescook@...omium.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        "H. Peter Anvin" <hpa@...or.com>, Joerg Roedel <joro@...tes.org>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Paolo Bonzini <pbonzini@...hat.com>
Subject: [PATCH v3 11/13] KVM: x86: SVM: use smram structs

This removes the last user of put_smstate/GET_SMSTATE so
remove these functions as well.

Also add a sanity check that we don't attempt to enter the SMM
on non long mode capable guest CPU with a running nested guest.

Signed-off-by: Maxim Levitsky <mlevitsk@...hat.com>
---
 arch/x86/include/asm/kvm_host.h |  6 ------
 arch/x86/kvm/svm/svm.c          | 21 ++++++---------------
 2 files changed, 6 insertions(+), 21 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index d752fabde94ad2..d570ec522ebb55 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -2077,12 +2077,6 @@ static inline int kvm_cpu_get_apicid(int mps_cpu)
 #endif
 }
 
-#define put_smstate(type, buf, offset, val)                      \
-	*(type *)((buf) + (offset) - 0x7e00) = val
-
-#define GET_SMSTATE(type, buf, offset)		\
-	(*(type *)((buf) + (offset) - 0x7e00))
-
 int kvm_cpu_dirty_log_size(void);
 
 int memslot_rmap_alloc(struct kvm_memory_slot *slot, unsigned long npages);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 688315d1dfabd1..7ca5e06878e19a 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4439,15 +4439,11 @@ static int svm_enter_smm(struct kvm_vcpu *vcpu, union kvm_smram *smram)
 	struct kvm_host_map map_save;
 	int ret;
 
-	char *smstate = (char *)smram;
-
 	if (!is_guest_mode(vcpu))
 		return 0;
 
-	/* FED8h - SVM Guest */
-	put_smstate(u64, smstate, 0x7ed8, 1);
-	/* FEE0h - SVM Guest VMCB Physical Address */
-	put_smstate(u64, smstate, 0x7ee0, svm->nested.vmcb12_gpa);
+	smram->smram64.svm_guest_flag = 1;
+	smram->smram64.svm_guest_vmcb_gpa = svm->nested.vmcb12_gpa;
 
 	svm->vmcb->save.rax = vcpu->arch.regs[VCPU_REGS_RAX];
 	svm->vmcb->save.rsp = vcpu->arch.regs[VCPU_REGS_RSP];
@@ -4486,28 +4482,23 @@ static int svm_leave_smm(struct kvm_vcpu *vcpu, const union kvm_smram *smram)
 {
 	struct vcpu_svm *svm = to_svm(vcpu);
 	struct kvm_host_map map, map_save;
-	u64 saved_efer, vmcb12_gpa;
 	struct vmcb *vmcb12;
 	int ret;
 
-	const char *smstate = (const char *)smram;
-
 	if (!guest_cpuid_has(vcpu, X86_FEATURE_LM))
 		return 0;
 
 	/* Non-zero if SMI arrived while vCPU was in guest mode. */
-	if (!GET_SMSTATE(u64, smstate, 0x7ed8))
+	if (!smram->smram64.svm_guest_flag)
 		return 0;
 
 	if (!guest_cpuid_has(vcpu, X86_FEATURE_SVM))
 		return 1;
 
-	saved_efer = GET_SMSTATE(u64, smstate, 0x7ed0);
-	if (!(saved_efer & EFER_SVME))
+	if (!(smram->smram64.efer & EFER_SVME))
 		return 1;
 
-	vmcb12_gpa = GET_SMSTATE(u64, smstate, 0x7ee0);
-	if (kvm_vcpu_map(vcpu, gpa_to_gfn(vmcb12_gpa), &map) == -EINVAL)
+	if (kvm_vcpu_map(vcpu, gpa_to_gfn(smram->smram64.svm_guest_vmcb_gpa), &map) == -EINVAL)
 		return 1;
 
 	ret = 1;
@@ -4533,7 +4524,7 @@ static int svm_leave_smm(struct kvm_vcpu *vcpu, const union kvm_smram *smram)
 	vmcb12 = map.hva;
 	nested_copy_vmcb_control_to_cache(svm, &vmcb12->control);
 	nested_copy_vmcb_save_to_cache(svm, &vmcb12->save);
-	ret = enter_svm_guest_mode(vcpu, vmcb12_gpa, vmcb12, false);
+	ret = enter_svm_guest_mode(vcpu, smram->smram64.svm_guest_vmcb_gpa, vmcb12, false);
 
 	if (ret)
 		goto unmap_save;
-- 
2.26.3