On Sun, Feb 11, 2018 at 11:29:44AM +0800, Wanpeng Li wrote:
> From: Wanpeng Li <wanpengli@xxxxxxxxxxx>
>
> This patch introduces dedicated vCPUs hint KVM_HINTS_DEDICATED,
> guest checks this feature bit to determine if they run on dedicated
> vCPUs, allowing optimizations.
>
> Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> Cc: Radim Krčmář <rkrcmar@xxxxxxxxxx>
> Cc: Eduardo Habkost <ehabkost@xxxxxxxxxx>
> Signed-off-by: Wanpeng Li <wanpengli@xxxxxxxxxxx>
> ---
> Documentation/virtual/kvm/cpuid.txt | 12 +++++++++++-
> arch/mips/include/asm/kvm_para.h | 5 +++++
> arch/powerpc/include/asm/kvm_para.h | 5 +++++
> arch/s390/include/asm/kvm_para.h | 5 +++++
> arch/x86/include/asm/kvm_para.h | 6 ++++++
> arch/x86/include/uapi/asm/kvm_para.h | 8 ++++++--
> arch/x86/kernel/kvm.c | 5 +++++
> include/asm-generic/kvm_para.h | 5 +++++
> include/linux/kvm_para.h | 5 +++++
> 9 files changed, 53 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/virtual/kvm/cpuid.txt b/Documentation/virtual/kvm/cpuid.txt
> index dcab6dc..e283b88 100644
> --- a/Documentation/virtual/kvm/cpuid.txt
> +++ b/Documentation/virtual/kvm/cpuid.txt
> @@ -23,7 +23,7 @@ This function queries the presence of KVM cpuid leafs.
>
>
> function: define KVM_CPUID_FEATURES (0x40000001)
> -returns : ebx, ecx, edx = 0
> +returns : ebx, ecx
> eax = and OR'ed group of (1 << flag), where each flags is:
Now that the above line is getting repeated, we should fix it: s/and/an/
>
>
> @@ -62,3 +62,13 @@ KVM_FEATURE_CLOCKSOURCE_STABLE_BIT || 24 || host will warn if no guest-side
> || || per-cpu warps are expected in
> || || kvmclock.
> ------------------------------------------------------------------------------
> +
> + edx = and OR'ed group of (1 << flag), where each flags is:
And then copy the corrected version here.
Thanks,
drew
> +
> +
> +flag || value || meaning
> +================================================================================
> +KVM_HINTS_DEDICATED || 0 || guest checks this feature bit
> + || || to determine if they run on dedicated
> + || || vCPUs, allowing optimizations
> +---------------------------------------------------------------------------------
> diff --git a/arch/mips/include/asm/kvm_para.h b/arch/mips/include/asm/kvm_para.h
> index 60b1aa0..bd1f4ee 100644
> --- a/arch/mips/include/asm/kvm_para.h
> +++ b/arch/mips/include/asm/kvm_para.h
> @@ -94,6 +94,11 @@ static inline unsigned int kvm_arch_para_features(void)
> return 0;
> }
>
> +static inline unsigned int kvm_arch_hint_features(void)
> +{
> + return 0;
> +}
> +
> #ifdef CONFIG_MIPS_PARAVIRT
> static inline bool kvm_para_available(void)
> {
> diff --git a/arch/powerpc/include/asm/kvm_para.h b/arch/powerpc/include/asm/kvm_para.h
> index 336a91a..8e58c00 100644
> --- a/arch/powerpc/include/asm/kvm_para.h
> +++ b/arch/powerpc/include/asm/kvm_para.h
> @@ -61,6 +61,11 @@ static inline unsigned int kvm_arch_para_features(void)
> return r;
> }
>
> +static inline unsigned int kvm_arch_hint_features(void)
> +{
> + return 0;
> +}
> +
> static inline bool kvm_check_and_clear_guest_paused(void)
> {
> return false;
> diff --git a/arch/s390/include/asm/kvm_para.h b/arch/s390/include/asm/kvm_para.h
> index 74eeec9..b2c935c 100644
> --- a/arch/s390/include/asm/kvm_para.h
> +++ b/arch/s390/include/asm/kvm_para.h
> @@ -193,6 +193,11 @@ static inline unsigned int kvm_arch_para_features(void)
> return 0;
> }
>
> +static inline unsigned int kvm_arch_hint_features(void)
> +{
> + return 0;
> +}
> +
> static inline bool kvm_check_and_clear_guest_paused(void)
> {
> return false;
> diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h
> index 7b407dd..2c7d368 100644
> --- a/arch/x86/include/asm/kvm_para.h
> +++ b/arch/x86/include/asm/kvm_para.h
> @@ -88,6 +88,7 @@ static inline long kvm_hypercall4(unsigned int nr, unsigned long p1,
> #ifdef CONFIG_KVM_GUEST
> bool kvm_para_available(void);
> unsigned int kvm_arch_para_features(void);
> +unsigned int kvm_arch_hint_features(void);
> void kvm_async_pf_task_wait(u32 token, int interrupt_kernel);
> void kvm_async_pf_task_wake(u32 token);
> u32 kvm_read_and_reset_pf_reason(void);
> @@ -115,6 +116,11 @@ static inline unsigned int kvm_arch_para_features(void)
> return 0;
> }
>
> +static inline unsigned int kvm_arch_hint_features(void)
> +{
> + return 0;
> +}
> +
> static inline u32 kvm_read_and_reset_pf_reason(void)
> {
> return 0;
> diff --git a/arch/x86/include/uapi/asm/kvm_para.h b/arch/x86/include/uapi/asm/kvm_para.h
> index 7a2ade4..e8f5dfb 100644
> --- a/arch/x86/include/uapi/asm/kvm_para.h
> +++ b/arch/x86/include/uapi/asm/kvm_para.h
> @@ -10,8 +10,10 @@
> */
> #define KVM_CPUID_SIGNATURE 0x40000000
>
> -/* This CPUID returns a feature bitmap in eax. Before enabling a particular
> - * paravirtualization, the appropriate feature bit should be checked.
> +/* This CPUID returns two feature bitmaps in eax, edx. Before enabling
> + * a particular paravirtualization, the appropriate feature bit should
> + * be checked in eax. The performance hint feature bit should be checked
> + * in edx.
> */
> #define KVM_CPUID_FEATURES 0x40000001
> #define KVM_FEATURE_CLOCKSOURCE 0
> @@ -27,6 +29,8 @@
> #define KVM_FEATURE_PV_UNHALT 7
> #define KVM_FEATURE_PV_TLB_FLUSH 9
>
> +#define KVM_HINTS_DEDICATED 0
> +
> /* The last 8 bits are used to indicate how to interpret the flags field
> * in pvclock structure. If no bits are set, all flags are ignored.
> */
> diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
> index 4e37d1a..77a0723 100644
> --- a/arch/x86/kernel/kvm.c
> +++ b/arch/x86/kernel/kvm.c
> @@ -604,6 +604,11 @@ unsigned int kvm_arch_para_features(void)
> return cpuid_eax(kvm_cpuid_base() | KVM_CPUID_FEATURES);
> }
>
> +unsigned int kvm_arch_hint_features(void)
> +{
> + return cpuid_edx(kvm_cpuid_base() | KVM_CPUID_FEATURES);
> +}
> +
> static uint32_t __init kvm_detect(void)
> {
> return kvm_cpuid_base();
> diff --git a/include/asm-generic/kvm_para.h b/include/asm-generic/kvm_para.h
> index 18c6abe..93e133d 100644
> --- a/include/asm-generic/kvm_para.h
> +++ b/include/asm-generic/kvm_para.h
> @@ -19,6 +19,11 @@ static inline unsigned int kvm_arch_para_features(void)
> return 0;
> }
>
> +static inline unsigned int kvm_arch_hint_features(void)
> +{
> + return 0;
> +}
> +
> static inline bool kvm_para_available(void)
> {
> return false;
> diff --git a/include/linux/kvm_para.h b/include/linux/kvm_para.h
> index 51f6ef2..30503b7 100644
> --- a/include/linux/kvm_para.h
> +++ b/include/linux/kvm_para.h
> @@ -9,4 +9,9 @@ static inline bool kvm_para_has_feature(unsigned int feature)
> {
> return !!(kvm_arch_para_features() & (1UL << feature));
> }
> +
> +static inline bool kvm_hint_has_feature(unsigned int feature)
> +{
> + return !!(kvm_arch_hint_features() & (1UL << feature));
> +}
> #endif /* __LINUX_KVM_PARA_H */
> --
> 2.7.4
>
