Patchwork [08/28] i386: kvm: set CPUID_EXT_HYPERVISOR on kvm_arch_get_supported_cpuid()

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Submitter Marcelo Tosatti
Date Oct. 31, 2012, 9:39 a.m.
Message ID <84bd945cf298650096691509e7e9170036605e02.1351676406.git.mtosatti@redhat.com>
Download mbox | patch
Permalink /patch/195843/
State New
Headers show

Comments

Marcelo Tosatti - Oct. 31, 2012, 9:39 a.m.
From: Eduardo Habkost <ehabkost@redhat.com>

Full grep for kvm_arch_get_supported_cpuid:

   kvm.h:uint32_t kvm_arch_get_supported_cpuid(KVMState *env, uint32_t function,
   target-i386/cpu.c:        x86_cpu_def->cpuid_7_0_ebx_features = kvm_arch_get_supported_cpuid(kvm_state, 0x7, 0, R_EBX);
   target-i386/cpu.c:            *eax = kvm_arch_get_supported_cpuid(s, 0xA, count, R_EAX);
   target-i386/cpu.c:            *ebx = kvm_arch_get_supported_cpuid(s, 0xA, count, R_EBX);
   target-i386/cpu.c:            *ecx = kvm_arch_get_supported_cpuid(s, 0xA, count, R_ECX);
   target-i386/cpu.c:            *edx = kvm_arch_get_supported_cpuid(s, 0xA, count, R_EDX);
   target-i386/cpu.c:            *eax = kvm_arch_get_supported_cpuid(s, 0xd, count, R_EAX);
   target-i386/cpu.c:            *ebx = kvm_arch_get_supported_cpuid(s, 0xd, count, R_EBX);
   target-i386/cpu.c:            *ecx = kvm_arch_get_supported_cpuid(s, 0xd, count, R_ECX);
   target-i386/cpu.c:            *edx = kvm_arch_get_supported_cpuid(s, 0xd, count, R_EDX);
   target-i386/kvm.c:uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function,
   target-i386/kvm.c:        cpuid_1_edx = kvm_arch_get_supported_cpuid(s, 1, 0, R_EDX);
   target-i386/kvm.c:    env->cpuid_features &= kvm_arch_get_supported_cpuid(s, 1, 0, R_EDX);
 * target-i386/kvm.c:    env->cpuid_ext_features &= kvm_arch_get_supported_cpuid(s, 1, 0, R_ECX);
   target-i386/kvm.c:    env->cpuid_ext2_features &= kvm_arch_get_supported_cpuid(s, 0x80000001,
   target-i386/kvm.c:    env->cpuid_ext3_features &= kvm_arch_get_supported_cpuid(s, 0x80000001,
   target-i386/kvm.c:    env->cpuid_svm_features  &= kvm_arch_get_supported_cpuid(s, 0x8000000A,
   target-i386/kvm.c:        kvm_arch_get_supported_cpuid(s, KVM_CPUID_FEATURES, 0, R_EAX);
   target-i386/kvm.c:            kvm_arch_get_supported_cpuid(s, 0xC0000001, 0, R_EDX);

Note that there is only one call for CPUID[1].ECX above (*), and it is
the one that gets hacked to include CPUID_EXT_HYPERVISOR, so we can
simply make kvm_arch_get_supported_cpuid() set it, to let the rest of
the code automatically know that the flag can be safely set by QEMU.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
---
 target-i386/kvm.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

Patch

diff --git a/target-i386/kvm.c b/target-i386/kvm.c
index 1f943c5..aabac72 100644
--- a/target-i386/kvm.c
+++ b/target-i386/kvm.c
@@ -196,6 +196,11 @@  uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function,
     if (function == 1 && reg == R_EDX) {
         /* KVM before 2.6.30 misreports the following features */
         ret |= CPUID_MTRR | CPUID_PAT | CPUID_MCE | CPUID_MCA;
+    } else if (function == 1 && reg == R_ECX) {
+        /* We can set the hypervisor flag, even if KVM does not return it on
+         * GET_SUPPORTED_CPUID
+         */
+        ret |= CPUID_EXT_HYPERVISOR;
     } else if (function == 0x80000001 && reg == R_EDX) {
         /* On Intel, kvm returns cpuid according to the Intel spec,
          * so add missing bits according to the AMD spec:
@@ -399,10 +404,8 @@  int kvm_arch_init_vcpu(CPUX86State *env)
 
     env->cpuid_features &= kvm_arch_get_supported_cpuid(s, 1, 0, R_EDX);
 
-    i = env->cpuid_ext_features & CPUID_EXT_HYPERVISOR;
     j = env->cpuid_ext_features & CPUID_EXT_TSC_DEADLINE_TIMER;
     env->cpuid_ext_features &= kvm_arch_get_supported_cpuid(s, 1, 0, R_ECX);
-    env->cpuid_ext_features |= i;
     if (j && kvm_irqchip_in_kernel() &&
         kvm_check_extension(s, KVM_CAP_TSC_DEADLINE_TIMER)) {
         env->cpuid_ext_features |= CPUID_EXT_TSC_DEADLINE_TIMER;