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| author | Eugene Korenevsky <ekorenevsky@gmail.com> | 2015-03-29 23:56:12 +0300 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2015-04-08 10:46:56 +0200 |
| commit | 5a4f55cde81f1633cb7ae9f0963b722e47acdc36 (patch) | |
| tree | 8350e79b1b046374a5b4658dc498a3f8b1e8b8f5 /arch/x86/kvm/x86.c | |
| parent | 80f0e95d1b221688b2608e0a80134e7acccd9a89 (diff) | |
| download | lwn-5a4f55cde81f1633cb7ae9f0963b722e47acdc36.tar.gz lwn-5a4f55cde81f1633cb7ae9f0963b722e47acdc36.zip | |
KVM: x86: cache maxphyaddr CPUID leaf in struct kvm_vcpu
cpuid_maxphyaddr(), which performs lot of memory accesses is called
extensively across KVM, especially in nVMX code.
This patch adds a cached value of maxphyaddr to vcpu.arch to reduce the
pressure onto CPU cache and simplify the code of cpuid_maxphyaddr()
callers. The cached value is initialized in kvm_arch_vcpu_init() and
reloaded every time CPUID is updated by usermode. It is obvious that
these reloads occur infrequently.
Signed-off-by: Eugene Korenevsky <ekorenevsky@gmail.com>
Message-Id: <20150329205612.GA1223@gnote>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/x86.c')
| -rw-r--r-- | arch/x86/kvm/x86.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 50861dd15a94..a578629acb42 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -7317,6 +7317,8 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu) vcpu->arch.guest_supported_xcr0 = 0; vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET; + vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu); + kvm_async_pf_hash_reset(vcpu); kvm_pmu_init(vcpu); |