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| author | Jan Beulich <jbeulich@suse.com> | 2013-06-25 15:57:44 +0200 |
|---|---|---|
| committer | Jan Beulich <jbeulich@suse.com> | 2013-06-25 15:57:44 +0200 |
| commit | 7f2e992b824ec62a2818e64390ac2ccfbd74e6b7 (patch) | |
| tree | bf3c525ba824282cd00ae49e78e168407ea10504 | |
| parent | 28d386fc4341683af86f6c3fde544e1651715ffd (diff) | |
| download | xen-7f2e992b824ec62a2818e64390ac2ccfbd74e6b7.tar.gz xen-7f2e992b824ec62a2818e64390ac2ccfbd74e6b7.tar.bz2 xen-7f2e992b824ec62a2818e64390ac2ccfbd74e6b7.zip | |
VMX/Viridian: suppress MSR-based APIC suggestion when having APIC-V
When the CPU has the necessary capabilities, having Windows use
synthetic MSR reads/writes is bogus, as this still requires emulation
(which is pretty much guaranteed to be slower than having the hardware
carry out the operation).
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Paul Durrant <paul.durrant@citrix.com>
Acked-by: George Dunlap <george.dunlap@eu.citrix.com>
| -rw-r--r-- | xen/arch/x86/hvm/viridian.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/xen/arch/x86/hvm/viridian.c b/xen/arch/x86/hvm/viridian.c index 1ee0f7fec8..46492cbb32 100644 --- a/xen/arch/x86/hvm/viridian.c +++ b/xen/arch/x86/hvm/viridian.c @@ -87,8 +87,9 @@ int cpuid_viridian_leaves(unsigned int leaf, unsigned int *eax, if ( (d->arch.hvm_domain.viridian.guest_os_id.raw == 0) || (d->arch.hvm_domain.viridian.guest_os_id.fields.os < 4) ) break; - *eax = (CPUID4A_MSR_BASED_APIC | - CPUID4A_RELAX_TIMER_INT); + *eax = CPUID4A_RELAX_TIMER_INT; + if ( !cpu_has_vmx_apic_reg_virt ) + *eax |= CPUID4A_MSR_BASED_APIC; *ebx = 2047; /* long spin count */ break; } |