| Message ID | 20200429104144.17816-1-liuwe@microsoft.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | x86/hyperv: stash and use the configured max VP index | expand |
On Wed, Apr 29, 2020 at 11:41:44AM +0100, Wei Liu wrote: > The value returned from CPUID is the maximum number for virtual > processors supported by Hyper-V. It could be larger than the maximum > number of virtual processors configured. > > Stash the configured number into a variable and use it in calculations. > > Signed-off-by: Wei Liu <liuwe@microsoft.com> > --- > xen/arch/x86/guest/hyperv/hyperv.c | 4 ++++ > xen/arch/x86/guest/hyperv/private.h | 1 + > xen/arch/x86/guest/hyperv/tlb.c | 2 +- > xen/arch/x86/guest/hyperv/util.c | 2 +- > 4 files changed, 7 insertions(+), 2 deletions(-) > > diff --git a/xen/arch/x86/guest/hyperv/hyperv.c b/xen/arch/x86/guest/hyperv/hyperv.c > index 91a6782cd986..84221b751453 100644 > --- a/xen/arch/x86/guest/hyperv/hyperv.c > +++ b/xen/arch/x86/guest/hyperv/hyperv.c > @@ -33,6 +33,7 @@ DEFINE_PER_CPU_READ_MOSTLY(void *, hv_input_page); > DEFINE_PER_CPU_READ_MOSTLY(void *, hv_vp_assist); > DEFINE_PER_CPU_READ_MOSTLY(unsigned int, hv_vp_index); > > +unsigned int __read_mostly hv_max_vp_index; > static bool __read_mostly hcall_page_ready; > > static uint64_t generate_guest_id(void) > @@ -143,6 +144,9 @@ static int setup_hypercall_pcpu_arg(void) > rdmsrl(HV_X64_MSR_VP_INDEX, vp_index_msr); > this_cpu(hv_vp_index) = vp_index_msr; > > + if ( vp_index_msr > hv_max_vp_index ) > + hv_max_vp_index = vp_index_msr; > + > return 0; > } > > diff --git a/xen/arch/x86/guest/hyperv/private.h b/xen/arch/x86/guest/hyperv/private.h > index 354fc7f685a7..fea3e291e944 100644 > --- a/xen/arch/x86/guest/hyperv/private.h > +++ b/xen/arch/x86/guest/hyperv/private.h > @@ -28,6 +28,7 @@ > DECLARE_PER_CPU(void *, hv_input_page); > DECLARE_PER_CPU(void *, hv_vp_assist); > DECLARE_PER_CPU(unsigned int, hv_vp_index); > +extern unsigned int hv_max_vp_index; > > static inline unsigned int hv_vp_index(unsigned int cpu) > { > diff --git a/xen/arch/x86/guest/hyperv/tlb.c b/xen/arch/x86/guest/hyperv/tlb.c > index 1d723d6ee679..0a44071481bd 100644 > --- a/xen/arch/x86/guest/hyperv/tlb.c > +++ b/xen/arch/x86/guest/hyperv/tlb.c > @@ -166,7 +166,7 @@ int hyperv_flush_tlb(const cpumask_t *mask, const void *va, > { > unsigned int vpid = hv_vp_index(cpu); > > - if ( vpid >= ms_hyperv.max_vp_index ) > + if ( vpid >= hv_max_vp_index ) I think the >= should be changed to > here. Wei. > { > local_irq_restore(irq_flags); > return -ENXIO; > diff --git a/xen/arch/x86/guest/hyperv/util.c b/xen/arch/x86/guest/hyperv/util.c > index bec61c2afd87..2c5f421b7bd9 100644 > --- a/xen/arch/x86/guest/hyperv/util.c > +++ b/xen/arch/x86/guest/hyperv/util.c > @@ -33,7 +33,7 @@ int cpumask_to_vpset(struct hv_vpset *vpset, > { > int nr = 1; > unsigned int cpu, vcpu_bank, vcpu_offset; > - unsigned int max_banks = ms_hyperv.max_vp_index / 64; > + unsigned int max_banks = hv_max_vp_index / 64; > > /* Up to 64 banks can be represented by valid_bank_mask */ > if ( max_banks > 64 ) > -- > 2.20.1 >
On Wed, Apr 29, 2020 at 11:47:18AM +0000, Wei Liu wrote: > On Wed, Apr 29, 2020 at 11:41:44AM +0100, Wei Liu wrote: > > The value returned from CPUID is the maximum number for virtual > > processors supported by Hyper-V. It could be larger than the maximum > > number of virtual processors configured. > > > > Stash the configured number into a variable and use it in calculations. > > > > Signed-off-by: Wei Liu <liuwe@microsoft.com> > > --- > > xen/arch/x86/guest/hyperv/hyperv.c | 4 ++++ > > xen/arch/x86/guest/hyperv/private.h | 1 + > > xen/arch/x86/guest/hyperv/tlb.c | 2 +- > > xen/arch/x86/guest/hyperv/util.c | 2 +- > > 4 files changed, 7 insertions(+), 2 deletions(-) > > > > diff --git a/xen/arch/x86/guest/hyperv/hyperv.c b/xen/arch/x86/guest/hyperv/hyperv.c > > index 91a6782cd986..84221b751453 100644 > > --- a/xen/arch/x86/guest/hyperv/hyperv.c > > +++ b/xen/arch/x86/guest/hyperv/hyperv.c > > @@ -33,6 +33,7 @@ DEFINE_PER_CPU_READ_MOSTLY(void *, hv_input_page); > > DEFINE_PER_CPU_READ_MOSTLY(void *, hv_vp_assist); > > DEFINE_PER_CPU_READ_MOSTLY(unsigned int, hv_vp_index); > > > > +unsigned int __read_mostly hv_max_vp_index; > > static bool __read_mostly hcall_page_ready; > > > > static uint64_t generate_guest_id(void) > > @@ -143,6 +144,9 @@ static int setup_hypercall_pcpu_arg(void) > > rdmsrl(HV_X64_MSR_VP_INDEX, vp_index_msr); > > this_cpu(hv_vp_index) = vp_index_msr; > > > > + if ( vp_index_msr > hv_max_vp_index ) > > + hv_max_vp_index = vp_index_msr; > > + > > return 0; > > } > > > > diff --git a/xen/arch/x86/guest/hyperv/private.h b/xen/arch/x86/guest/hyperv/private.h > > index 354fc7f685a7..fea3e291e944 100644 > > --- a/xen/arch/x86/guest/hyperv/private.h > > +++ b/xen/arch/x86/guest/hyperv/private.h > > @@ -28,6 +28,7 @@ > > DECLARE_PER_CPU(void *, hv_input_page); > > DECLARE_PER_CPU(void *, hv_vp_assist); > > DECLARE_PER_CPU(unsigned int, hv_vp_index); > > +extern unsigned int hv_max_vp_index; > > > > static inline unsigned int hv_vp_index(unsigned int cpu) > > { > > diff --git a/xen/arch/x86/guest/hyperv/tlb.c b/xen/arch/x86/guest/hyperv/tlb.c > > index 1d723d6ee679..0a44071481bd 100644 > > --- a/xen/arch/x86/guest/hyperv/tlb.c > > +++ b/xen/arch/x86/guest/hyperv/tlb.c > > @@ -166,7 +166,7 @@ int hyperv_flush_tlb(const cpumask_t *mask, const void *va, > > { > > unsigned int vpid = hv_vp_index(cpu); > > > > - if ( vpid >= ms_hyperv.max_vp_index ) > > + if ( vpid >= hv_max_vp_index ) > > I think the >= should be changed to > here. I agree. With this fixed: Reviewed-by: Roger Pau Monné <roger.pau@citrix.com> Thanks!
On Thu, Apr 30, 2020 at 12:15:58PM +0200, Roger Pau Monné wrote: > On Wed, Apr 29, 2020 at 11:47:18AM +0000, Wei Liu wrote: > > On Wed, Apr 29, 2020 at 11:41:44AM +0100, Wei Liu wrote: > > > The value returned from CPUID is the maximum number for virtual > > > processors supported by Hyper-V. It could be larger than the maximum > > > number of virtual processors configured. > > > > > > Stash the configured number into a variable and use it in calculations. > > > > > > Signed-off-by: Wei Liu <liuwe@microsoft.com> > > > --- > > > xen/arch/x86/guest/hyperv/hyperv.c | 4 ++++ > > > xen/arch/x86/guest/hyperv/private.h | 1 + > > > xen/arch/x86/guest/hyperv/tlb.c | 2 +- > > > xen/arch/x86/guest/hyperv/util.c | 2 +- > > > 4 files changed, 7 insertions(+), 2 deletions(-) > > > > > > diff --git a/xen/arch/x86/guest/hyperv/hyperv.c b/xen/arch/x86/guest/hyperv/hyperv.c > > > index 91a6782cd986..84221b751453 100644 > > > --- a/xen/arch/x86/guest/hyperv/hyperv.c > > > +++ b/xen/arch/x86/guest/hyperv/hyperv.c > > > @@ -33,6 +33,7 @@ DEFINE_PER_CPU_READ_MOSTLY(void *, hv_input_page); > > > DEFINE_PER_CPU_READ_MOSTLY(void *, hv_vp_assist); > > > DEFINE_PER_CPU_READ_MOSTLY(unsigned int, hv_vp_index); > > > > > > +unsigned int __read_mostly hv_max_vp_index; > > > static bool __read_mostly hcall_page_ready; > > > > > > static uint64_t generate_guest_id(void) > > > @@ -143,6 +144,9 @@ static int setup_hypercall_pcpu_arg(void) > > > rdmsrl(HV_X64_MSR_VP_INDEX, vp_index_msr); > > > this_cpu(hv_vp_index) = vp_index_msr; > > > > > > + if ( vp_index_msr > hv_max_vp_index ) > > > + hv_max_vp_index = vp_index_msr; > > > + > > > return 0; > > > } > > > > > > diff --git a/xen/arch/x86/guest/hyperv/private.h b/xen/arch/x86/guest/hyperv/private.h > > > index 354fc7f685a7..fea3e291e944 100644 > > > --- a/xen/arch/x86/guest/hyperv/private.h > > > +++ b/xen/arch/x86/guest/hyperv/private.h > > > @@ -28,6 +28,7 @@ > > > DECLARE_PER_CPU(void *, hv_input_page); > > > DECLARE_PER_CPU(void *, hv_vp_assist); > > > DECLARE_PER_CPU(unsigned int, hv_vp_index); > > > +extern unsigned int hv_max_vp_index; > > > > > > static inline unsigned int hv_vp_index(unsigned int cpu) > > > { > > > diff --git a/xen/arch/x86/guest/hyperv/tlb.c b/xen/arch/x86/guest/hyperv/tlb.c > > > index 1d723d6ee679..0a44071481bd 100644 > > > --- a/xen/arch/x86/guest/hyperv/tlb.c > > > +++ b/xen/arch/x86/guest/hyperv/tlb.c > > > @@ -166,7 +166,7 @@ int hyperv_flush_tlb(const cpumask_t *mask, const void *va, > > > { > > > unsigned int vpid = hv_vp_index(cpu); > > > > > > - if ( vpid >= ms_hyperv.max_vp_index ) > > > + if ( vpid >= hv_max_vp_index ) > > > > I think the >= should be changed to > here. > > I agree. With this fixed: > > Reviewed-by: Roger Pau Monné <roger.pau@citrix.com> FWIW, I think it should also be nice to add an ASSERT_UNREACHABLE in the if body, as now it shouldn't be possible for vpid to be greater than hv_max_vp_index unless something has gone really wrong? Roger.
On Thu, Apr 30, 2020 at 12:21:18PM +0200, Roger Pau Monné wrote: > On Thu, Apr 30, 2020 at 12:15:58PM +0200, Roger Pau Monné wrote: > > On Wed, Apr 29, 2020 at 11:47:18AM +0000, Wei Liu wrote: > > > On Wed, Apr 29, 2020 at 11:41:44AM +0100, Wei Liu wrote: > > > > The value returned from CPUID is the maximum number for virtual > > > > processors supported by Hyper-V. It could be larger than the maximum > > > > number of virtual processors configured. > > > > > > > > Stash the configured number into a variable and use it in calculations. > > > > > > > > Signed-off-by: Wei Liu <liuwe@microsoft.com> > > > > --- > > > > xen/arch/x86/guest/hyperv/hyperv.c | 4 ++++ > > > > xen/arch/x86/guest/hyperv/private.h | 1 + > > > > xen/arch/x86/guest/hyperv/tlb.c | 2 +- > > > > xen/arch/x86/guest/hyperv/util.c | 2 +- > > > > 4 files changed, 7 insertions(+), 2 deletions(-) > > > > > > > > diff --git a/xen/arch/x86/guest/hyperv/hyperv.c b/xen/arch/x86/guest/hyperv/hyperv.c > > > > index 91a6782cd986..84221b751453 100644 > > > > --- a/xen/arch/x86/guest/hyperv/hyperv.c > > > > +++ b/xen/arch/x86/guest/hyperv/hyperv.c > > > > @@ -33,6 +33,7 @@ DEFINE_PER_CPU_READ_MOSTLY(void *, hv_input_page); > > > > DEFINE_PER_CPU_READ_MOSTLY(void *, hv_vp_assist); > > > > DEFINE_PER_CPU_READ_MOSTLY(unsigned int, hv_vp_index); > > > > > > > > +unsigned int __read_mostly hv_max_vp_index; > > > > static bool __read_mostly hcall_page_ready; > > > > > > > > static uint64_t generate_guest_id(void) > > > > @@ -143,6 +144,9 @@ static int setup_hypercall_pcpu_arg(void) > > > > rdmsrl(HV_X64_MSR_VP_INDEX, vp_index_msr); > > > > this_cpu(hv_vp_index) = vp_index_msr; > > > > > > > > + if ( vp_index_msr > hv_max_vp_index ) > > > > + hv_max_vp_index = vp_index_msr; > > > > + > > > > return 0; > > > > } > > > > > > > > diff --git a/xen/arch/x86/guest/hyperv/private.h b/xen/arch/x86/guest/hyperv/private.h > > > > index 354fc7f685a7..fea3e291e944 100644 > > > > --- a/xen/arch/x86/guest/hyperv/private.h > > > > +++ b/xen/arch/x86/guest/hyperv/private.h > > > > @@ -28,6 +28,7 @@ > > > > DECLARE_PER_CPU(void *, hv_input_page); > > > > DECLARE_PER_CPU(void *, hv_vp_assist); > > > > DECLARE_PER_CPU(unsigned int, hv_vp_index); > > > > +extern unsigned int hv_max_vp_index; > > > > > > > > static inline unsigned int hv_vp_index(unsigned int cpu) > > > > { > > > > diff --git a/xen/arch/x86/guest/hyperv/tlb.c b/xen/arch/x86/guest/hyperv/tlb.c > > > > index 1d723d6ee679..0a44071481bd 100644 > > > > --- a/xen/arch/x86/guest/hyperv/tlb.c > > > > +++ b/xen/arch/x86/guest/hyperv/tlb.c > > > > @@ -166,7 +166,7 @@ int hyperv_flush_tlb(const cpumask_t *mask, const void *va, > > > > { > > > > unsigned int vpid = hv_vp_index(cpu); > > > > > > > > - if ( vpid >= ms_hyperv.max_vp_index ) > > > > + if ( vpid >= hv_max_vp_index ) > > > > > > I think the >= should be changed to > here. > > > > I agree. With this fixed: > > > > Reviewed-by: Roger Pau Monné <roger.pau@citrix.com> > > FWIW, I think it should also be nice to add an ASSERT_UNREACHABLE in > the if body, as now it shouldn't be possible for vpid to be greater > than hv_max_vp_index unless something has gone really wrong? At some point I will initialise vpid to (uint32_t)-1 so it could go over hv_max_vp_index if there is a bug in code. Wei. > > Roger.
diff --git a/xen/arch/x86/guest/hyperv/hyperv.c b/xen/arch/x86/guest/hyperv/hyperv.c index 91a6782cd986..84221b751453 100644 --- a/xen/arch/x86/guest/hyperv/hyperv.c +++ b/xen/arch/x86/guest/hyperv/hyperv.c @@ -33,6 +33,7 @@ DEFINE_PER_CPU_READ_MOSTLY(void *, hv_input_page); DEFINE_PER_CPU_READ_MOSTLY(void *, hv_vp_assist); DEFINE_PER_CPU_READ_MOSTLY(unsigned int, hv_vp_index); +unsigned int __read_mostly hv_max_vp_index; static bool __read_mostly hcall_page_ready; static uint64_t generate_guest_id(void) @@ -143,6 +144,9 @@ static int setup_hypercall_pcpu_arg(void) rdmsrl(HV_X64_MSR_VP_INDEX, vp_index_msr); this_cpu(hv_vp_index) = vp_index_msr; + if ( vp_index_msr > hv_max_vp_index ) + hv_max_vp_index = vp_index_msr; + return 0; } diff --git a/xen/arch/x86/guest/hyperv/private.h b/xen/arch/x86/guest/hyperv/private.h index 354fc7f685a7..fea3e291e944 100644 --- a/xen/arch/x86/guest/hyperv/private.h +++ b/xen/arch/x86/guest/hyperv/private.h @@ -28,6 +28,7 @@ DECLARE_PER_CPU(void *, hv_input_page); DECLARE_PER_CPU(void *, hv_vp_assist); DECLARE_PER_CPU(unsigned int, hv_vp_index); +extern unsigned int hv_max_vp_index; static inline unsigned int hv_vp_index(unsigned int cpu) { diff --git a/xen/arch/x86/guest/hyperv/tlb.c b/xen/arch/x86/guest/hyperv/tlb.c index 1d723d6ee679..0a44071481bd 100644 --- a/xen/arch/x86/guest/hyperv/tlb.c +++ b/xen/arch/x86/guest/hyperv/tlb.c @@ -166,7 +166,7 @@ int hyperv_flush_tlb(const cpumask_t *mask, const void *va, { unsigned int vpid = hv_vp_index(cpu); - if ( vpid >= ms_hyperv.max_vp_index ) + if ( vpid >= hv_max_vp_index ) { local_irq_restore(irq_flags); return -ENXIO; diff --git a/xen/arch/x86/guest/hyperv/util.c b/xen/arch/x86/guest/hyperv/util.c index bec61c2afd87..2c5f421b7bd9 100644 --- a/xen/arch/x86/guest/hyperv/util.c +++ b/xen/arch/x86/guest/hyperv/util.c @@ -33,7 +33,7 @@ int cpumask_to_vpset(struct hv_vpset *vpset, { int nr = 1; unsigned int cpu, vcpu_bank, vcpu_offset; - unsigned int max_banks = ms_hyperv.max_vp_index / 64; + unsigned int max_banks = hv_max_vp_index / 64; /* Up to 64 banks can be represented by valid_bank_mask */ if ( max_banks > 64 )
The value returned from CPUID is the maximum number for virtual processors supported by Hyper-V. It could be larger than the maximum number of virtual processors configured. Stash the configured number into a variable and use it in calculations. Signed-off-by: Wei Liu <liuwe@microsoft.com> --- xen/arch/x86/guest/hyperv/hyperv.c | 4 ++++ xen/arch/x86/guest/hyperv/private.h | 1 + xen/arch/x86/guest/hyperv/tlb.c | 2 +- xen/arch/x86/guest/hyperv/util.c | 2 +- 4 files changed, 7 insertions(+), 2 deletions(-)