Message ID | 1363024736-2650-2-git-send-email-jjherne@us.ibm.com |
---|---|
State | New |
Headers | show |
On 11/03/13 18:58, Jason J. Herne wrote: > We want to avoid expensive register synchronization IOCTL's on the hot path so > a new kvm_s390_get_registers_partial() is introduced as a compliment to > kvm_arch_get_registers(). The new function is called on the hot path, and > kvm_arch_get_registers() is called when we need the complete runtime register > state. > > kvm_arch_put_registers() is updated to only sync the partial runtime set when > we've only dirtied the partial runtime set. This is to avoid sending bad data > back to KVM if we've only partially synced the runtime register set. > > Signed-off-by: Jason J. Herne <jjherne@us.ibm.com> > Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Alex, we have this code in our private tree (the one thats used by the testers) for a while now and it seems to work fine. This should be ok to apply. Since this also fixes the problem that s390 has not a complete view of the kvm registers in places were we want it (dump etc) we might even consider this a bugfix. Your take if this is still good for 1.5. Christian > --- > target-s390x/cpu.h | 17 +++++++++++++ > target-s390x/kvm.c | 67 ++++++++++++++++++++++++++++++++++++++++++++++++++++ > 2 files changed, 84 insertions(+) > > diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h > index 9cb739d..69ecb05 100644 > --- a/target-s390x/cpu.h > +++ b/target-s390x/cpu.h > @@ -78,6 +78,11 @@ typedef struct MchkQueue { > uint16_t type; > } MchkQueue; > > +/* Defined values for CPUS390XState.runtime_reg_dirty_mask */ > +#define KVM_S390_RUNTIME_DIRTY_NONE 0 > +#define KVM_S390_RUNTIME_DIRTY_PARTIAL 1 > +#define KVM_S390_RUNTIME_DIRTY_FULL 2 > + > typedef struct CPUS390XState { > uint64_t regs[16]; /* GP registers */ > CPU_DoubleU fregs[16]; /* FP registers */ > @@ -121,6 +126,13 @@ typedef struct CPUS390XState { > uint64_t cputm; > uint32_t todpr; > > + /* on S390 the runtime register set has two dirty states: > + * a partial dirty state in which only the registers that > + * are needed all the time are fetched. And a fully dirty > + * state in which all runtime registers are fetched. > + */ > + uint32_t runtime_reg_dirty_mask; > + > CPU_COMMON > > /* reset does memset(0) up to here */ > @@ -1068,6 +1080,7 @@ void kvm_s390_io_interrupt(S390CPU *cpu, uint16_t subchannel_id, > uint32_t io_int_word); > void kvm_s390_crw_mchk(S390CPU *cpu); > void kvm_s390_enable_css_support(S390CPU *cpu); > +int kvm_s390_get_registers_partial(CPUState *cpu); > #else > static inline void kvm_s390_io_interrupt(S390CPU *cpu, > uint16_t subchannel_id, > @@ -1082,6 +1095,10 @@ static inline void kvm_s390_crw_mchk(S390CPU *cpu) > static inline void kvm_s390_enable_css_support(S390CPU *cpu) > { > } > +static inline int kvm_s390_get_registers_partial(CPUState *cpu) > +{ > + return -ENOSYS; > +} > #endif > > static inline void s390_io_interrupt(S390CPU *cpu, > diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c > index 8f111ae..934757e 100644 > --- a/target-s390x/kvm.c > +++ b/target-s390x/kvm.c > @@ -123,6 +123,7 @@ int kvm_arch_put_registers(CPUState *cs, int level) > { > S390CPU *cpu = S390_CPU(cs); > CPUS390XState *env = &cpu->env; > + struct kvm_one_reg reg; > struct kvm_sregs sregs; > struct kvm_regs regs; > int ret; > @@ -147,6 +148,30 @@ int kvm_arch_put_registers(CPUState *cs, int level) > } > } > > + if (env->runtime_reg_dirty_mask == KVM_S390_RUNTIME_DIRTY_FULL) { > + reg.id = KVM_REG_S390_CPU_TIMER; > + reg.addr = (__u64)&(env->cputm); > + ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, ®); > + if (ret < 0) { > + return ret; > + } > + > + reg.id = KVM_REG_S390_CLOCK_COMP; > + reg.addr = (__u64)&(env->ckc); > + ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, ®); > + if (ret < 0) { > + return ret; > + } > + > + reg.id = KVM_REG_S390_TODPR; > + reg.addr = (__u64)&(env->todpr); > + ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, ®); > + if (ret < 0) { > + return ret; > + } > + } > + env->runtime_reg_dirty_mask = KVM_S390_RUNTIME_DIRTY_NONE; > + > /* Do we need to save more than that? */ > if (level == KVM_PUT_RUNTIME_STATE) { > return 0; > @@ -186,11 +211,52 @@ int kvm_arch_get_registers(CPUState *cs) > { > S390CPU *cpu = S390_CPU(cs); > CPUS390XState *env = &cpu->env; > + struct kvm_one_reg reg; > + int r; > + > + r = kvm_s390_get_registers_partial(cs); > + if (r < 0) { > + return r; > + } > + > + reg.id = KVM_REG_S390_CPU_TIMER; > + reg.addr = (__u64)&(env->cputm); > + r = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, ®); > + if (r < 0) { > + return r; > + } > + > + reg.id = KVM_REG_S390_CLOCK_COMP; > + reg.addr = (__u64)&(env->ckc); > + r = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, ®); > + if (r < 0) { > + return r; > + } > + > + reg.id = KVM_REG_S390_TODPR; > + reg.addr = (__u64)&(env->todpr); > + r = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, ®); > + if (r < 0) { > + return r; > + } > + > + env->runtime_reg_dirty_mask = KVM_S390_RUNTIME_DIRTY_FULL; > + return 0; > +} > + > +int kvm_s390_get_registers_partial(CPUState *cs) > +{ > + S390CPU *cpu = S390_CPU(cs); > + CPUS390XState *env = &cpu->env; > struct kvm_sregs sregs; > struct kvm_regs regs; > int ret; > int i; > > + if (env->runtime_reg_dirty_mask) { > + return 0; > + } > + > /* get the PSW */ > env->psw.addr = cs->kvm_run->psw_addr; > env->psw.mask = cs->kvm_run->psw_mask; > @@ -236,6 +302,7 @@ int kvm_arch_get_registers(CPUState *cs) > /* no prefix without sync regs */ > } > > + env->runtime_reg_dirty_mask = KVM_S390_RUNTIME_DIRTY_PARTIAL; > return 0; > } >
diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h index 9cb739d..69ecb05 100644 --- a/target-s390x/cpu.h +++ b/target-s390x/cpu.h @@ -78,6 +78,11 @@ typedef struct MchkQueue { uint16_t type; } MchkQueue; +/* Defined values for CPUS390XState.runtime_reg_dirty_mask */ +#define KVM_S390_RUNTIME_DIRTY_NONE 0 +#define KVM_S390_RUNTIME_DIRTY_PARTIAL 1 +#define KVM_S390_RUNTIME_DIRTY_FULL 2 + typedef struct CPUS390XState { uint64_t regs[16]; /* GP registers */ CPU_DoubleU fregs[16]; /* FP registers */ @@ -121,6 +126,13 @@ typedef struct CPUS390XState { uint64_t cputm; uint32_t todpr; + /* on S390 the runtime register set has two dirty states: + * a partial dirty state in which only the registers that + * are needed all the time are fetched. And a fully dirty + * state in which all runtime registers are fetched. + */ + uint32_t runtime_reg_dirty_mask; + CPU_COMMON /* reset does memset(0) up to here */ @@ -1068,6 +1080,7 @@ void kvm_s390_io_interrupt(S390CPU *cpu, uint16_t subchannel_id, uint32_t io_int_word); void kvm_s390_crw_mchk(S390CPU *cpu); void kvm_s390_enable_css_support(S390CPU *cpu); +int kvm_s390_get_registers_partial(CPUState *cpu); #else static inline void kvm_s390_io_interrupt(S390CPU *cpu, uint16_t subchannel_id, @@ -1082,6 +1095,10 @@ static inline void kvm_s390_crw_mchk(S390CPU *cpu) static inline void kvm_s390_enable_css_support(S390CPU *cpu) { } +static inline int kvm_s390_get_registers_partial(CPUState *cpu) +{ + return -ENOSYS; +} #endif static inline void s390_io_interrupt(S390CPU *cpu, diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c index 8f111ae..934757e 100644 --- a/target-s390x/kvm.c +++ b/target-s390x/kvm.c @@ -123,6 +123,7 @@ int kvm_arch_put_registers(CPUState *cs, int level) { S390CPU *cpu = S390_CPU(cs); CPUS390XState *env = &cpu->env; + struct kvm_one_reg reg; struct kvm_sregs sregs; struct kvm_regs regs; int ret; @@ -147,6 +148,30 @@ int kvm_arch_put_registers(CPUState *cs, int level) } } + if (env->runtime_reg_dirty_mask == KVM_S390_RUNTIME_DIRTY_FULL) { + reg.id = KVM_REG_S390_CPU_TIMER; + reg.addr = (__u64)&(env->cputm); + ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, ®); + if (ret < 0) { + return ret; + } + + reg.id = KVM_REG_S390_CLOCK_COMP; + reg.addr = (__u64)&(env->ckc); + ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, ®); + if (ret < 0) { + return ret; + } + + reg.id = KVM_REG_S390_TODPR; + reg.addr = (__u64)&(env->todpr); + ret = kvm_vcpu_ioctl(cs, KVM_SET_ONE_REG, ®); + if (ret < 0) { + return ret; + } + } + env->runtime_reg_dirty_mask = KVM_S390_RUNTIME_DIRTY_NONE; + /* Do we need to save more than that? */ if (level == KVM_PUT_RUNTIME_STATE) { return 0; @@ -186,11 +211,52 @@ int kvm_arch_get_registers(CPUState *cs) { S390CPU *cpu = S390_CPU(cs); CPUS390XState *env = &cpu->env; + struct kvm_one_reg reg; + int r; + + r = kvm_s390_get_registers_partial(cs); + if (r < 0) { + return r; + } + + reg.id = KVM_REG_S390_CPU_TIMER; + reg.addr = (__u64)&(env->cputm); + r = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, ®); + if (r < 0) { + return r; + } + + reg.id = KVM_REG_S390_CLOCK_COMP; + reg.addr = (__u64)&(env->ckc); + r = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, ®); + if (r < 0) { + return r; + } + + reg.id = KVM_REG_S390_TODPR; + reg.addr = (__u64)&(env->todpr); + r = kvm_vcpu_ioctl(cs, KVM_GET_ONE_REG, ®); + if (r < 0) { + return r; + } + + env->runtime_reg_dirty_mask = KVM_S390_RUNTIME_DIRTY_FULL; + return 0; +} + +int kvm_s390_get_registers_partial(CPUState *cs) +{ + S390CPU *cpu = S390_CPU(cs); + CPUS390XState *env = &cpu->env; struct kvm_sregs sregs; struct kvm_regs regs; int ret; int i; + if (env->runtime_reg_dirty_mask) { + return 0; + } + /* get the PSW */ env->psw.addr = cs->kvm_run->psw_addr; env->psw.mask = cs->kvm_run->psw_mask; @@ -236,6 +302,7 @@ int kvm_arch_get_registers(CPUState *cs) /* no prefix without sync regs */ } + env->runtime_reg_dirty_mask = KVM_S390_RUNTIME_DIRTY_PARTIAL; return 0; }