| Message ID | 1740611284-27506-5-git-send-email-nunodasneves@linux.microsoft.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Introduce /dev/mshv root partition driver | expand |
On Wed, Feb 26, 2025 at 03:07:58PM -0800, Nuno Das Neves wrote: > Factor out the check for enabling auto eoi, to be reused in root > partition code. > Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
On 2/26/2025 3:07 PM, Nuno Das Neves wrote: > Factor out the check for enabling auto eoi, to be reused in root > partition code. > > Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> > --- I think adding "No functional changes" would bring some benefit: that's an additional invariant to check against when reviewing.
On 2/26/2025 3:07 PM, Nuno Das Neves wrote: > Factor out the check for enabling auto eoi, to be reused in root > partition code. > > Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> > --- > drivers/hv/hv.c | 12 +----------- > include/asm-generic/mshyperv.h | 13 +++++++++++++ > 2 files changed, 14 insertions(+), 11 deletions(-) > <snip> > diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h > index 258034dfd829..1f46d19a16aa 100644 > --- a/include/asm-generic/mshyperv.h > +++ b/include/asm-generic/mshyperv.h > @@ -77,6 +77,19 @@ extern u64 hv_do_fast_hypercall16(u16 control, u64 input1, u64 input2); > bool hv_isolation_type_snp(void); > bool hv_isolation_type_tdx(void); > > +/* > + * On architectures where Hyper-V doesn't support AEOI (e.g., ARM64), > + * it doesn't provide a recommendation flag and AEOI must be disabled. > + */ > +static inline bool hv_recommend_using_aeoi(void) > +{ > +#ifdef HV_DEPRECATING_AEOI_RECOMMENDED > + return !(ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED); > +#else > + return false; > +#endif > +} > + I must be missing something very basic here, and if so, I apologize, and please enlighten me. HV_DEPRECATING_AEOI_RECOMMENDED is defined as BIT(9) in include/hyperv/hvgdk_mini.h, and asm-generic/mshyperv.h includes that via include/hyperv/hvhdk.h. If this is the case, when would HV_DEPRECATING_AEOI_RECOMMENDED ever be not defined? If it's always defined, do we need the #ifdef? Thanks, Easwar (he/him)
On 2/27/2025 10:04 AM, Roman Kisel wrote: > > > On 2/26/2025 3:07 PM, Nuno Das Neves wrote: >> Factor out the check for enabling auto eoi, to be reused in root >> partition code. >> >> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> >> --- > > I think adding "No functional changes" would bring some benefit: > that's an additional invariant to check against when reviewing. > Thanks, I can add it for next version :)
On 2/27/2025 3:03 PM, Easwar Hariharan wrote: > On 2/26/2025 3:07 PM, Nuno Das Neves wrote: >> Factor out the check for enabling auto eoi, to be reused in root >> partition code. >> >> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> >> --- >> drivers/hv/hv.c | 12 +----------- >> include/asm-generic/mshyperv.h | 13 +++++++++++++ >> 2 files changed, 14 insertions(+), 11 deletions(-) >> > > <snip> > >> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h >> index 258034dfd829..1f46d19a16aa 100644 >> --- a/include/asm-generic/mshyperv.h >> +++ b/include/asm-generic/mshyperv.h >> @@ -77,6 +77,19 @@ extern u64 hv_do_fast_hypercall16(u16 control, u64 input1, u64 input2); >> bool hv_isolation_type_snp(void); >> bool hv_isolation_type_tdx(void); >> >> +/* >> + * On architectures where Hyper-V doesn't support AEOI (e.g., ARM64), >> + * it doesn't provide a recommendation flag and AEOI must be disabled. >> + */ >> +static inline bool hv_recommend_using_aeoi(void) >> +{ >> +#ifdef HV_DEPRECATING_AEOI_RECOMMENDED >> + return !(ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED); >> +#else >> + return false; >> +#endif >> +} >> + > > I must be missing something very basic here, and if so, I apologize, and please enlighten me. > > HV_DEPRECATING_AEOI_RECOMMENDED is defined as BIT(9) in include/hyperv/hvgdk_mini.h, and > asm-generic/mshyperv.h includes that via include/hyperv/hvhdk.h. > > If this is the case, when would HV_DEPRECATING_AEOI_RECOMMENDED ever be not defined? > If it's always defined, do we need the #ifdef? > HV_DEPRECATING_AEOI_RECOMMENDED is only defined on x86 (it used to live in x86 hyperv-tlfs.h). It lives inside a #if defined(CONFIG_X86) block in hvgdk_mini.h. It is a bit confusing since it is surrounded by other x86-only definitions which are prefixed with HV_X64_. Thanks Nuno > Thanks, > Easwar (he/him)
On 2/27/2025 4:33 PM, Nuno Das Neves wrote: > On 2/27/2025 3:03 PM, Easwar Hariharan wrote: >> On 2/26/2025 3:07 PM, Nuno Das Neves wrote: >>> Factor out the check for enabling auto eoi, to be reused in root >>> partition code. >>> >>> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> >>> --- >>> drivers/hv/hv.c | 12 +----------- >>> include/asm-generic/mshyperv.h | 13 +++++++++++++ >>> 2 files changed, 14 insertions(+), 11 deletions(-) >>> >> >> <snip> >> >>> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h >>> index 258034dfd829..1f46d19a16aa 100644 >>> --- a/include/asm-generic/mshyperv.h >>> +++ b/include/asm-generic/mshyperv.h >>> @@ -77,6 +77,19 @@ extern u64 hv_do_fast_hypercall16(u16 control, u64 input1, u64 input2); >>> bool hv_isolation_type_snp(void); >>> bool hv_isolation_type_tdx(void); >>> >>> +/* >>> + * On architectures where Hyper-V doesn't support AEOI (e.g., ARM64), >>> + * it doesn't provide a recommendation flag and AEOI must be disabled. >>> + */ >>> +static inline bool hv_recommend_using_aeoi(void) >>> +{ >>> +#ifdef HV_DEPRECATING_AEOI_RECOMMENDED >>> + return !(ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED); >>> +#else >>> + return false; >>> +#endif >>> +} >>> + >> >> I must be missing something very basic here, and if so, I apologize, and please enlighten me. >> >> HV_DEPRECATING_AEOI_RECOMMENDED is defined as BIT(9) in include/hyperv/hvgdk_mini.h, and >> asm-generic/mshyperv.h includes that via include/hyperv/hvhdk.h. >> >> If this is the case, when would HV_DEPRECATING_AEOI_RECOMMENDED ever be not defined? >> If it's always defined, do we need the #ifdef? >> > HV_DEPRECATING_AEOI_RECOMMENDED is only defined on x86 (it used to live in x86 hyperv-tlfs.h). > It lives inside a #if defined(CONFIG_X86) block in hvgdk_mini.h. It is a bit confusing since > it is surrounded by other x86-only definitions which are prefixed with HV_X64_. > Ah, thank you. I knew it must be something glaringly obvious in hindsight. With that resolved, Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com>
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c index a38f84548bc2..308c8f279df8 100644 --- a/drivers/hv/hv.c +++ b/drivers/hv/hv.c @@ -313,17 +313,7 @@ void hv_synic_enable_regs(unsigned int cpu) shared_sint.vector = vmbus_interrupt; shared_sint.masked = false; - - /* - * On architectures where Hyper-V doesn't support AEOI (e.g., ARM64), - * it doesn't provide a recommendation flag and AEOI must be disabled. - */ -#ifdef HV_DEPRECATING_AEOI_RECOMMENDED - shared_sint.auto_eoi = - !(ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED); -#else - shared_sint.auto_eoi = 0; -#endif + shared_sint.auto_eoi = hv_recommend_using_aeoi(); hv_set_msr(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64); /* Enable the global synic bit */ diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h index 258034dfd829..1f46d19a16aa 100644 --- a/include/asm-generic/mshyperv.h +++ b/include/asm-generic/mshyperv.h @@ -77,6 +77,19 @@ extern u64 hv_do_fast_hypercall16(u16 control, u64 input1, u64 input2); bool hv_isolation_type_snp(void); bool hv_isolation_type_tdx(void); +/* + * On architectures where Hyper-V doesn't support AEOI (e.g., ARM64), + * it doesn't provide a recommendation flag and AEOI must be disabled. + */ +static inline bool hv_recommend_using_aeoi(void) +{ +#ifdef HV_DEPRECATING_AEOI_RECOMMENDED + return !(ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED); +#else + return false; +#endif +} + static inline struct hv_proximity_domain_info hv_numa_node_to_pxm_info(int node) { struct hv_proximity_domain_info pxm_info = {};
Factor out the check for enabling auto eoi, to be reused in root partition code. Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> --- drivers/hv/hv.c | 12 +----------- include/asm-generic/mshyperv.h | 13 +++++++++++++ 2 files changed, 14 insertions(+), 11 deletions(-)