lkml.org 
[lkml]   [2014]   [Feb]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 3.12 012/133] x86, kvm: cache the base of the KVM cpuid leaves
    Date
    3.12-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Paolo Bonzini <pbonzini@redhat.com>

    commit 1c300a40772dae829b91dad634999a6a522c0829 upstream.

    It is unnecessary to go through hypervisor_cpuid_base every time
    a leaf is found (which will be every time a feature is requested
    after the next patch).

    Fixes: 1085ba7f552d84aa8ac0ae903fa8d0cc2ff9f79d
    Cc: mtosatti@redhat.com
    Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    arch/x86/include/asm/kvm_para.h | 22 ++++++----------------
    arch/x86/kernel/kvm.c | 27 +++++++++++++++++++++++++++
    2 files changed, 33 insertions(+), 16 deletions(-)

    --- a/arch/x86/include/asm/kvm_para.h
    +++ b/arch/x86/include/asm/kvm_para.h
    @@ -85,28 +85,13 @@ static inline long kvm_hypercall4(unsign
    return ret;
    }

    -static inline uint32_t kvm_cpuid_base(void)
    -{
    - if (boot_cpu_data.cpuid_level < 0)
    - return 0; /* So we don't blow up on old processors */
    -
    - if (cpu_has_hypervisor)
    - return hypervisor_cpuid_base("KVMKVMKVM\0\0\0", 0);
    -
    - return 0;
    -}
    -
    -static inline bool kvm_para_available(void)
    -{
    - return kvm_cpuid_base() != 0;
    -}
    -
    static inline unsigned int kvm_arch_para_features(void)
    {
    return cpuid_eax(KVM_CPUID_FEATURES);
    }

    #ifdef CONFIG_KVM_GUEST
    +bool kvm_para_available(void);
    void __init kvm_guest_init(void);
    void kvm_async_pf_task_wait(u32 token);
    void kvm_async_pf_task_wake(u32 token);
    @@ -126,6 +111,11 @@ static inline void kvm_spinlock_init(voi
    #define kvm_async_pf_task_wait(T) do {} while(0)
    #define kvm_async_pf_task_wake(T) do {} while(0)

    +static inline bool kvm_para_available(void)
    +{
    + return 0;
    +}
    +
    static inline u32 kvm_read_and_reset_pf_reason(void)
    {
    return 0;
    --- a/arch/x86/kernel/kvm.c
    +++ b/arch/x86/kernel/kvm.c
    @@ -500,6 +500,33 @@ void __init kvm_guest_init(void)
    #endif
    }

    +static noinline uint32_t __kvm_cpuid_base(void)
    +{
    + if (boot_cpu_data.cpuid_level < 0)
    + return 0; /* So we don't blow up on old processors */
    +
    + if (cpu_has_hypervisor)
    + return hypervisor_cpuid_base("KVMKVMKVM\0\0\0", 0);
    +
    + return 0;
    +}
    +
    +static inline uint32_t kvm_cpuid_base(void)
    +{
    + static int kvm_cpuid_base = -1;
    +
    + if (kvm_cpuid_base == -1)
    + kvm_cpuid_base = __kvm_cpuid_base();
    +
    + return kvm_cpuid_base;
    +}
    +
    +bool kvm_para_available(void)
    +{
    + return kvm_cpuid_base() != 0;
    +}
    +EXPORT_SYMBOL_GPL(kvm_para_available);
    +
    static uint32_t __init kvm_detect(void)
    {
    return kvm_cpuid_base();



    \
     
     \ /
      Last update: 2014-02-05 00:21    [W:4.411 / U:0.140 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site