Re: [PATCH v2] asm-generic: Remove the parameters of the generate_guest_id function and modify the return type and modify the function name

Wei Liu
2022-09-23T10:29:24Z

Hi Kunyu

The subject line is far too long.

Please change it to

hyperv: simplify and rename generate_guest_id

On Tue, Sep 20, 2022 at 11:28:37AM +0800, Li kunyu wrote:
> 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.
>
> v2:
> Fix generate_guest_id to hv_generate_guest_id.

The patch version information shouldn't be part of the commit message.
You can use scissors to separate them

---8<---
v2: ...

When the patch gets applied, text after the scissors will be stripped
automatically.

>
> Signed-off-by: Li kunyu <kunyu@nfschina.com>

BTW, the previous patch was submitted by Li Zeming. Did you two agree on
who to take this forward?

> ---
> 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>
>
> 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)
^^
There are two spaces. We only need one.

I know it is not introduced by you, but since you're modifying the code
anyway, you may as well drop the extraneous space.

> {
> - __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
>