From 5908cb719ea51af7bed9d54bf3122c9d81e8ebc1 Mon Sep 17 00:00:00 2001
From: badger <badger@FreeBSD.org>
Date: Wed, 13 Jul 2016 19:19:18 +0000
Subject: [PATCH] Add explicit detection of KVM hypervisor

Set vm_guest to a new enum value (VM_GUEST_KVM) when kvm is detected and use
vm_guest in conditionals testing for KVM.

Also, fix a conditional checking if we're running in a VM which caught only
the generic VM case, but not more specific VMs (KVM, VMWare, etc.).  (Spotted
by: vangyzen).

Differential revision:	https://reviews.freebsd.org/D7172
Sponsored by:	Dell Inc.
Approved by:	kib (mentor), vangyzen (mentor)
Reviewed by:	alc
MFC after:	4 weeks
---
 sys/amd64/amd64/pmap.c   | 2 +-
 sys/i386/i386/pmap.c     | 2 +-
 sys/kern/subr_param.c    | 1 +
 sys/sys/systm.h          | 2 +-
 sys/x86/x86/identcpu.c   | 2 ++
 sys/x86/x86/local_apic.c | 3 +--
 6 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/sys/amd64/amd64/pmap.c b/sys/amd64/amd64/pmap.c
index c41853220a73..52adb660c3d2 100644
--- a/sys/amd64/amd64/pmap.c
+++ b/sys/amd64/amd64/pmap.c
@@ -1224,7 +1224,7 @@ pmap_init(void)
 	 * include at least one feature that is only supported by older Intel
 	 * or newer AMD processors.
 	 */
-	if (vm_guest == VM_GUEST_VM && (cpu_feature & CPUID_SS) == 0 &&
+	if (vm_guest != VM_GUEST_NO && (cpu_feature & CPUID_SS) == 0 &&
 	    (cpu_feature2 & (CPUID2_SSSE3 | CPUID2_SSE41 | CPUID2_AESNI |
 	    CPUID2_AVX | CPUID2_XSAVE)) == 0 && (amd_feature2 & (AMDID2_XOP |
 	    AMDID2_FMA4)) == 0)
diff --git a/sys/i386/i386/pmap.c b/sys/i386/i386/pmap.c
index 575e42f28d7d..d40de0ff8b10 100644
--- a/sys/i386/i386/pmap.c
+++ b/sys/i386/i386/pmap.c
@@ -794,7 +794,7 @@ pmap_init(void)
 	 * include at least one feature that is only supported by older Intel
 	 * or newer AMD processors.
 	 */
-	if (vm_guest == VM_GUEST_VM && (cpu_feature & CPUID_SS) == 0 &&
+	if (vm_guest != VM_GUEST_NO && (cpu_feature & CPUID_SS) == 0 &&
 	    (cpu_feature2 & (CPUID2_SSSE3 | CPUID2_SSE41 | CPUID2_AESNI |
 	    CPUID2_AVX | CPUID2_XSAVE)) == 0 && (amd_feature2 & (AMDID2_XOP |
 	    AMDID2_FMA4)) == 0)
diff --git a/sys/kern/subr_param.c b/sys/kern/subr_param.c
index 65fb3e78d322..e48072c3a719 100644
--- a/sys/kern/subr_param.c
+++ b/sys/kern/subr_param.c
@@ -148,6 +148,7 @@ static const char *const vm_guest_sysctl_names[] = {
 	"xen",
 	"hv",
 	"vmware",
+	"kvm",
 	NULL
 };
 CTASSERT(nitems(vm_guest_sysctl_names) - 1 == VM_LAST);
diff --git a/sys/sys/systm.h b/sys/sys/systm.h
index dae6adc78687..dab9ee2f4393 100644
--- a/sys/sys/systm.h
+++ b/sys/sys/systm.h
@@ -74,7 +74,7 @@ extern int vm_guest;		/* Running as virtual machine guest? */
  * Keep in sync with vm_guest_sysctl_names[].
  */
 enum VM_GUEST { VM_GUEST_NO = 0, VM_GUEST_VM, VM_GUEST_XEN, VM_GUEST_HV,
-		VM_GUEST_VMWARE, VM_LAST };
+		VM_GUEST_VMWARE, VM_GUEST_KVM, VM_LAST };
 
 #if defined(WITNESS) || defined(INVARIANT_SUPPORT)
 void	kassert_panic(const char *fmt, ...)  __printflike(1, 2);
diff --git a/sys/x86/x86/identcpu.c b/sys/x86/x86/identcpu.c
index 48e07eaca3c8..152866f580b3 100644
--- a/sys/x86/x86/identcpu.c
+++ b/sys/x86/x86/identcpu.c
@@ -1300,6 +1300,8 @@ identify_hypervisor(void)
 				vm_guest = VM_GUEST_VMWARE;
 			else if (strcmp(hv_vendor, "Microsoft Hv") == 0)
 				vm_guest = VM_GUEST_HV;
+			else if (strcmp(hv_vendor, "KVMKVMKVM") == 0)
+				vm_guest = VM_GUEST_KVM;
 		}
 		return;
 	}
diff --git a/sys/x86/x86/local_apic.c b/sys/x86/x86/local_apic.c
index 203e9d00e8ac..cd774df1422c 100644
--- a/sys/x86/x86/local_apic.c
+++ b/sys/x86/x86/local_apic.c
@@ -499,8 +499,7 @@ native_lapic_init(vm_paddr_t addr)
 	ver = lapic_read32(LAPIC_VERSION);
 	if ((ver & APIC_VER_EOI_SUPPRESSION) != 0) {
 		lapic_eoi_suppression = 1;
-		if (vm_guest == VM_GUEST_VM &&
-		    !strcmp(hv_vendor, "KVMKVMKVM")) {
+		if (vm_guest == VM_GUEST_KVM) {
 			if (bootverbose)
 				printf(
 		       "KVM -- disabling lapic eoi suppression\n");