| Message ID | 1740611284-27506-3-git-send-email-nunodasneves@linux.microsoft.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Introduce /dev/mshv root partition driver | expand |
On Wed, Feb 26, 2025 at 03:07:56PM -0800, Nuno Das Neves wrote: > From: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> > > Extend the "ms_hyperv_info" structure to include a new field, > "ext_features", for capturing extended Hyper-V features. > Update the "ms_hyperv_init_platform" function to retrieve these features > using the cpuid instruction and include them in the informational output. > Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
On 2/26/2025 3:07 PM, Nuno Das Neves wrote: > From: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> [...] > > - pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, hints 0x%x, misc 0x%x\n", > - ms_hyperv.features, ms_hyperv.priv_high, ms_hyperv.hints, > + pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, ext 0x%x, hints 0x%x, misc 0x%x\n", > + ms_hyperv.features, ms_hyperv.priv_high, > + ms_hyperv.ext_features, ms_hyperv.hints, > ms_hyperv.misc_features); Would using %#x instead of 0x%x be better in your opinion? [..]
On 2/26/2025 3:07 PM, Nuno Das Neves wrote: > From: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> > > Extend the "ms_hyperv_info" structure to include a new field, > "ext_features", for capturing extended Hyper-V features. > Update the "ms_hyperv_init_platform" function to retrieve these features > using the cpuid instruction and include them in the informational output. > > Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> > Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> > --- > arch/x86/kernel/cpu/mshyperv.c | 6 ++++-- > include/asm-generic/mshyperv.h | 1 + > 2 files changed, 5 insertions(+), 2 deletions(-) Looks good to me. Reviewed-by: Easwar Hariharan <eahariha@linux.microsoft.com>
On 2/27/2025 9:59 AM, Roman Kisel wrote: > > > On 2/26/2025 3:07 PM, Nuno Das Neves wrote: >> From: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> > [...] >> - pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, hints 0x%x, misc 0x%x\n", >> - ms_hyperv.features, ms_hyperv.priv_high, ms_hyperv.hints, >> + pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, ext 0x%x, hints 0x%x, misc 0x%x\n", >> + ms_hyperv.features, ms_hyperv.priv_high, >> + ms_hyperv.ext_features, ms_hyperv.hints, >> ms_hyperv.misc_features); > > Would using %#x instead of 0x%x be better in your opinion? > It's a reasonable suggestion. I'm not sure if it's worth another version, if this patch seems good enough to merge as-is. However if I'm doing another version of this series that still includes this patch, then I can certainly make the change. Thanks! > [..]
On 2/27/2025 4:17 PM, Nuno Das Neves wrote: > On 2/27/2025 9:59 AM, Roman Kisel wrote: >> >> >> On 2/26/2025 3:07 PM, Nuno Das Neves wrote: >>> From: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> >> [...] >>> - pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, hints 0x%x, misc 0x%x\n", >>> - ms_hyperv.features, ms_hyperv.priv_high, ms_hyperv.hints, >>> + pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, ext 0x%x, hints 0x%x, misc 0x%x\n", >>> + ms_hyperv.features, ms_hyperv.priv_high, >>> + ms_hyperv.ext_features, ms_hyperv.hints, >>> ms_hyperv.misc_features); >> >> Would using %#x instead of 0x%x be better in your opinion? >> > It's a reasonable suggestion. I'm not sure if it's worth another > version, if this patch seems good enough to merge as-is. > However if I'm doing another version of this series that still > includes this patch, then I can certainly make the change. > You're right, a suggestion like that shouldn't warrant another version, agreed! Whether you implement that tweak or not, looks good to me. Reviewed-by: Roman Kisel <romank@linux.microsoft.com> > Thanks! > >> [..] >
From: Nuno Das Neves <nunodasneves@linux.microsoft.com> Sent: Wednesday, February 26, 2025 3:08 PM > > From: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> > > Extend the "ms_hyperv_info" structure to include a new field, > "ext_features", for capturing extended Hyper-V features. > Update the "ms_hyperv_init_platform" function to retrieve these features > using the cpuid instruction and include them in the informational output. > > Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> > Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> > --- > arch/x86/kernel/cpu/mshyperv.c | 6 ++++-- > include/asm-generic/mshyperv.h | 1 + > 2 files changed, 5 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c > index 4f01f424ea5b..2c29dfd6de19 100644 > --- a/arch/x86/kernel/cpu/mshyperv.c > +++ b/arch/x86/kernel/cpu/mshyperv.c > @@ -434,13 +434,15 @@ static void __init ms_hyperv_init_platform(void) > */ > ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES); > ms_hyperv.priv_high = cpuid_ebx(HYPERV_CPUID_FEATURES); > + ms_hyperv.ext_features = cpuid_ecx(HYPERV_CPUID_FEATURES); > ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES); > ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO); > > hv_max_functions_eax = cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS); > > - pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, hints 0x%x, misc 0x%x\n", > - ms_hyperv.features, ms_hyperv.priv_high, ms_hyperv.hints, > + pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, ext 0x%x, hints 0x%x, misc 0x%x\n", > + ms_hyperv.features, ms_hyperv.priv_high, > + ms_hyperv.ext_features, ms_hyperv.hints, > ms_hyperv.misc_features); > > ms_hyperv.max_vp_index = cpuid_eax(HYPERV_CPUID_IMPLEMENT_LIMITS); > diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h > index dc4729dba9ef..c020d5d0ec2a 100644 > --- a/include/asm-generic/mshyperv.h > +++ b/include/asm-generic/mshyperv.h > @@ -36,6 +36,7 @@ enum hv_partition_type { > struct ms_hyperv_info { > u32 features; > u32 priv_high; > + u32 ext_features; > u32 misc_features; > u32 hints; > u32 nested_features; > -- > 2.34.1 Are any of the extended features available on arm64? This code is obviously x86 specific, so ms_hyperv.ext_features will be zero on arm64. From what I can see, ext_features is referenced only in Patch 10 of this series, and in code that is under #ifdef CONFIG_X86_64, so that should be OK. The pr_info() line will now be slightly different on x86 and arm64 since arm64 won't have the "ext" field, but I think that's OK too. Reviewed-by: Michael Kelley <mhklinux@outlook.com>
On Thu, Feb 27, 2025 at 7:09 AM Nuno Das Neves <nunodasneves@linux.microsoft.com> wrote: > > From: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> > > Extend the "ms_hyperv_info" structure to include a new field, > "ext_features", for capturing extended Hyper-V features. > Update the "ms_hyperv_init_platform" function to retrieve these features > using the cpuid instruction and include them in the informational output. > > Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> > Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> > --- Reviewed-by: Tianyu Lan <tiala@microsoft.com>
On 3/6/2025 10:30 AM, Michael Kelley wrote: > From: Nuno Das Neves <nunodasneves@linux.microsoft.com> Sent: Wednesday, February 26, 2025 3:08 PM >> >> From: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> >> >> Extend the "ms_hyperv_info" structure to include a new field, >> "ext_features", for capturing extended Hyper-V features. >> Update the "ms_hyperv_init_platform" function to retrieve these features >> using the cpuid instruction and include them in the informational output. >> >> Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> >> Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com> >> --- >> arch/x86/kernel/cpu/mshyperv.c | 6 ++++-- >> include/asm-generic/mshyperv.h | 1 + >> 2 files changed, 5 insertions(+), 2 deletions(-) >> >> diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c >> index 4f01f424ea5b..2c29dfd6de19 100644 >> --- a/arch/x86/kernel/cpu/mshyperv.c >> +++ b/arch/x86/kernel/cpu/mshyperv.c >> @@ -434,13 +434,15 @@ static void __init ms_hyperv_init_platform(void) >> */ >> ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES); >> ms_hyperv.priv_high = cpuid_ebx(HYPERV_CPUID_FEATURES); >> + ms_hyperv.ext_features = cpuid_ecx(HYPERV_CPUID_FEATURES); >> ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES); >> ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO); >> >> hv_max_functions_eax = cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS); >> >> - pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, hints 0x%x, misc 0x%x\n", >> - ms_hyperv.features, ms_hyperv.priv_high, ms_hyperv.hints, >> + pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, ext 0x%x, hints 0x%x, misc 0x%x\n", >> + ms_hyperv.features, ms_hyperv.priv_high, >> + ms_hyperv.ext_features, ms_hyperv.hints, >> ms_hyperv.misc_features); >> >> ms_hyperv.max_vp_index = cpuid_eax(HYPERV_CPUID_IMPLEMENT_LIMITS); >> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h >> index dc4729dba9ef..c020d5d0ec2a 100644 >> --- a/include/asm-generic/mshyperv.h >> +++ b/include/asm-generic/mshyperv.h >> @@ -36,6 +36,7 @@ enum hv_partition_type { >> struct ms_hyperv_info { >> u32 features; >> u32 priv_high; >> + u32 ext_features; >> u32 misc_features; >> u32 hints; >> u32 nested_features; >> -- >> 2.34.1 > > Are any of the extended features available on arm64? This code is obviously x86 specific, > so ms_hyperv.ext_features will be zero on arm64. From what I can see, ext_features is > referenced only in Patch 10 of this series, and in code that is under #ifdef CONFIG_X86_64, > so that should be OK. Just checked - yes ARM64 has features in ECX, but they are different to the x86_64 ones. We can add the ARM64 ones when needed. Thanks Nuno > > The pr_info() line will now be slightly different on x86 and arm64 since arm64 won't have > the "ext" field, but I think that's OK too. > > Reviewed-by: Michael Kelley <mhklinux@outlook.com>
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 4f01f424ea5b..2c29dfd6de19 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -434,13 +434,15 @@ static void __init ms_hyperv_init_platform(void) */ ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES); ms_hyperv.priv_high = cpuid_ebx(HYPERV_CPUID_FEATURES); + ms_hyperv.ext_features = cpuid_ecx(HYPERV_CPUID_FEATURES); ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES); ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO); hv_max_functions_eax = cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS); - pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, hints 0x%x, misc 0x%x\n", - ms_hyperv.features, ms_hyperv.priv_high, ms_hyperv.hints, + pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, ext 0x%x, hints 0x%x, misc 0x%x\n", + ms_hyperv.features, ms_hyperv.priv_high, + ms_hyperv.ext_features, ms_hyperv.hints, ms_hyperv.misc_features); ms_hyperv.max_vp_index = cpuid_eax(HYPERV_CPUID_IMPLEMENT_LIMITS); diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h index dc4729dba9ef..c020d5d0ec2a 100644 --- a/include/asm-generic/mshyperv.h +++ b/include/asm-generic/mshyperv.h @@ -36,6 +36,7 @@ enum hv_partition_type { struct ms_hyperv_info { u32 features; u32 priv_high; + u32 ext_features; u32 misc_features; u32 hints; u32 nested_features;