Re: [PATCH 02/15] mshyperv: Introduce hv_get_hypervisor_version
From: Wei Liu
Date: Wed Aug 02 2023 - 19:40:08 EST
On Thu, Jul 27, 2023 at 12:54:37PM -0700, Nuno Das Neves wrote:
> x86_64 and arm64 implementations to get the hypervisor version
> information.
> Also introduce hv_hypervisor_version_info structure to simplify parsing
> the fields.
> Replace the existing parsing when printing the version numbers.
The line wrapping looks odd. When you resend, please fix it. If you
meant to use multiple paragraphs, please insert a blank line between
them.
x86 and ARM maintainers, I don't think there is anything particularly
interesting to you, but I guess you're CC'ed because some of the files
fall under the respective directories. Feel free to ignore this patch.
The code looks fine to me -- it is mostly just refactoring.
Thanks,
Wei.
>
> Signed-off-by: Nuno Das Neves <nunodasneves@xxxxxxxxxxxxxxxxxxx>
> ---
> arch/arm64/hyperv/mshyperv.c | 23 +++++++++++-------
> arch/x86/kernel/cpu/mshyperv.c | 40 ++++++++++++++++++++-----------
> include/asm-generic/hyperv-tlfs.h | 23 ++++++++++++++++++
> include/asm-generic/mshyperv.h | 2 ++
> 4 files changed, 66 insertions(+), 22 deletions(-)
>
> diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c
> index a406454578f0..d44c358ce45c 100644
> --- a/arch/arm64/hyperv/mshyperv.c
> +++ b/arch/arm64/hyperv/mshyperv.c
> @@ -19,10 +19,19 @@
>
> static bool hyperv_initialized;
>
> +int hv_get_hypervisor_version(union hv_hypervisor_version_info *info)
> +{
> + hv_get_vpreg_128(HV_REGISTER_HYPERVISOR_VERSION,
> + (struct hv_get_vp_registers_output *)info);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(hv_get_hypervisor_version);
> +
> static int __init hyperv_init(void)
> {
> - struct hv_get_vp_registers_output result;
> - u32 a, b, c, d;
> + struct hv_get_vp_registers_output result;
> + union hv_hypervisor_version_info version;
> u64 guest_id;
> int ret;
>
> @@ -55,13 +64,11 @@ static int __init hyperv_init(void)
> ms_hyperv.misc_features);
>
> /* Get information about the Hyper-V host version */
> - hv_get_vpreg_128(HV_REGISTER_HYPERVISOR_VERSION, &result);
> - a = result.as32.a;
> - b = result.as32.b;
> - c = result.as32.c;
> - d = result.as32.d;
> + hv_get_hypervisor_version(&version);
> pr_info("Hyper-V: Host Build %d.%d.%d.%d-%d-%d\n",
> - b >> 16, b & 0xFFFF, a, d & 0xFFFFFF, c, d >> 24);
> + version.major_version, version.minor_version,
> + version.build_number, version.service_number,
> + version.service_pack, version.service_branch);
>
> ret = hv_common_init();
> if (ret)
> diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
> index 57f6a5879b30..e44291e902ae 100644
> --- a/arch/x86/kernel/cpu/mshyperv.c
> +++ b/arch/x86/kernel/cpu/mshyperv.c
> @@ -328,13 +328,30 @@ static void __init hv_smp_prepare_cpus(unsigned int max_cpus)
> }
> #endif
>
> +int hv_get_hypervisor_version(union hv_hypervisor_version_info *info)
> +{
> + unsigned int hv_max_functions;
> +
> + hv_max_functions = cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS);
> + if (hv_max_functions < HYPERV_CPUID_VERSION) {
> + pr_err("%s: Could not detect Hyper-V version\n",
> + __func__);
> + return -ENODEV;
> + }
> +
> + info->eax = cpuid_eax(HYPERV_CPUID_VERSION);
> + info->ebx = cpuid_ebx(HYPERV_CPUID_VERSION);
> + info->ecx = cpuid_ecx(HYPERV_CPUID_VERSION);
> + info->edx = cpuid_edx(HYPERV_CPUID_VERSION);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL_GPL(hv_get_hypervisor_version);
> +
> static void __init ms_hyperv_init_platform(void)
> {
> int hv_max_functions_eax;
> - int hv_host_info_eax;
> - int hv_host_info_ebx;
> - int hv_host_info_ecx;
> - int hv_host_info_edx;
> + union hv_hypervisor_version_info version;
>
> #ifdef CONFIG_PARAVIRT
> pv_info.name = "Hyper-V";
> @@ -388,16 +405,11 @@ static void __init ms_hyperv_init_platform(void)
> /*
> * Extract host information.
> */
> - if (hv_max_functions_eax >= HYPERV_CPUID_VERSION) {
> - hv_host_info_eax = cpuid_eax(HYPERV_CPUID_VERSION);
> - hv_host_info_ebx = cpuid_ebx(HYPERV_CPUID_VERSION);
> - hv_host_info_ecx = cpuid_ecx(HYPERV_CPUID_VERSION);
> - hv_host_info_edx = cpuid_edx(HYPERV_CPUID_VERSION);
> -
> - pr_info("Hyper-V: Host Build %d.%d.%d.%d-%d-%d\n",
> - hv_host_info_ebx >> 16, hv_host_info_ebx & 0xFFFF,
> - hv_host_info_eax, hv_host_info_edx & 0xFFFFFF,
> - hv_host_info_ecx, hv_host_info_edx >> 24);
> + if (hv_get_hypervisor_version(&version) == 0) {
> + pr_info("Hyper-V Host Build:%d-%d.%d-%d-%d.%d\n",
> + version.build_number, version.major_version,
> + version.minor_version, version.service_pack,
> + version.service_branch, version.service_number);
> }
>
> if (ms_hyperv.features & HV_ACCESS_FREQUENCY_MSRS &&
> diff --git a/include/asm-generic/hyperv-tlfs.h b/include/asm-generic/hyperv-tlfs.h
> index f4e4cc4f965f..373f26efa18a 100644
> --- a/include/asm-generic/hyperv-tlfs.h
> +++ b/include/asm-generic/hyperv-tlfs.h
> @@ -786,6 +786,29 @@ struct hv_input_unmap_device_interrupt {
> #define HV_SOURCE_SHADOW_NONE 0x0
> #define HV_SOURCE_SHADOW_BRIDGE_BUS_RANGE 0x1
>
> +/*
> + * Version info reported by hypervisor
> + */
> +union hv_hypervisor_version_info {
> + struct {
> + u32 build_number;
> +
> + u32 minor_version : 16;
> + u32 major_version : 16;
> +
> + u32 service_pack;
> +
> + u32 service_number : 24;
> + u32 service_branch : 8;
> + };
> + struct {
> + u32 eax;
> + u32 ebx;
> + u32 ecx;
> + u32 edx;
> + };
> +};
> +
> /*
> * The whole argument should fit in a page to be able to pass to the hypervisor
> * in one hypercall.
> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
> index 094c57320ed1..233c976344e5 100644
> --- a/include/asm-generic/mshyperv.h
> +++ b/include/asm-generic/mshyperv.h
> @@ -153,6 +153,8 @@ static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type)
> }
> }
>
> +int hv_get_hypervisor_version(union hv_hypervisor_version_info *info);
> +
> void hv_setup_vmbus_handler(void (*handler)(void));
> void hv_remove_vmbus_handler(void);
> void hv_setup_stimer0_handler(void (*handler)(void));
> --
> 2.25.1
>