RE: [PATCH v3] hyperv: simplify and rename generate_guest_id

From: Michael Kelley (LINUX)
Date: Fri Sep 23 2022 - 16:28:06 EST


From: Li kunyu <kunyu@xxxxxxxxxxxx> Sent: Friday, September 23, 2022 4:43 AM
>
> The generate_guest_id function is more suitable for use after the
> following modifications.
> 1. Modify the type of the guest_id variable to u64, which is compatible
> with the caller.
> 2. Remove all parameters from the function, and write the parameter
> (LINUX_VERSION_CODE) passed in by the actual call into the function
> implementation.
> 3. Rename the function to make it clearly a Hyper-V related function,
> and modify it to hv_generate_guest_id.
>
> Signed-off-by: Li kunyu <kunyu@xxxxxxxxxxxx>
>
> --------
> v2: Fix generate_guest_id to hv_generate_guest_id.
> v3: Fix [PATCH v2] asm-generic: Remove the ... to [PATCH v3] hyperv: simp
> lify ... and remove extra spaces
> ---
> arch/arm64/hyperv/mshyperv.c | 2 +-
> arch/x86/hyperv/hv_init.c | 2 +-
> include/asm-generic/mshyperv.h | 12 +++++-------
> 3 files changed, 7 insertions(+), 9 deletions(-)
>
> diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c
> index bbbe351e9045..3863fd226e0e 100644
> --- a/arch/arm64/hyperv/mshyperv.c
> +++ b/arch/arm64/hyperv/mshyperv.c
> @@ -38,7 +38,7 @@ static int __init hyperv_init(void)
> return 0;
>
> /* Setup the guest ID */
> - guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0);
> + guest_id = hv_generate_guest_id();
> hv_set_vpreg(HV_REGISTER_GUEST_OSID, guest_id);
>
> /* Get the features and hints from Hyper-V */
> diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
> index 3de6d8b53367..93770791b858 100644
> --- a/arch/x86/hyperv/hv_init.c
> +++ b/arch/x86/hyperv/hv_init.c
> @@ -426,7 +426,7 @@ void __init hyperv_init(void)
> * 1. Register the guest ID
> * 2. Enable the hypercall and register the hypercall page
> */
> - guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0);
> + guest_id = hv_generate_guest_id();
> wrmsrl(HV_X64_MSR_GUEST_OS_ID, guest_id);
>
> /* Hyper-V requires to write guest os id via ghcb in SNP IVM. */
> diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h
> index c05d2ce9b6cd..7f4a23cee56f 100644
> --- a/include/asm-generic/mshyperv.h
> +++ b/include/asm-generic/mshyperv.h
> @@ -25,6 +25,7 @@
> #include <linux/nmi.h>
> #include <asm/ptrace.h>
> #include <asm/hyperv-tlfs.h>
> +#include <linux/version.h>

Having added the #include of linux/version.h here, you should remove it
from arch/arm64/hyperv/mshyperv.c and arch/x86/hyperv/hv_init.c.
It shouldn't be needed any longer in those two files.

Michael

>
> struct ms_hyperv_info {
> u32 features;
> @@ -105,15 +106,12 @@ static inline u64 hv_do_rep_hypercall(u16 code, u16 rep_count, u16 varhead_size,
> }
>
> /* Generate the guest OS identifier as described in the Hyper-V TLFS */
> -static inline __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version,
> - __u64 d_info2)
> +static inline u64 hv_generate_guest_id(void)
> {
> - __u64 guest_id = 0;
> + u64 guest_id;
>
> - guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48);
> - guest_id |= (d_info1 << 48);
> - guest_id |= (kernel_version << 16);
> - guest_id |= d_info2;
> + guest_id = (((u64)HV_LINUX_VENDOR_ID) << 48);
> + guest_id |= (((u64)LINUX_VERSION_CODE) << 16);
>
> return guest_id;
> }
> --
> 2.18.2