Re: [PATCH] x86/hyperv: Fix hv_get/set_register for nested bringup
From: Wei Liu
Date: Mon Feb 13 2023 - 09:29:17 EST
A few comments on style.
On Thu, Feb 09, 2023 at 02:02:52PM -0800, Nuno Das Neves wrote:
> hv_get_nested_reg only translates SINT0, resulting in the wrong sint
> being registered by nested vmbus.
Please put a blank line between paragraphs.
> Fix the issue with new utility function hv_is_sint_reg.
> While at it, improve clarity of hv_set_non_nested_register and hv_is_synic_reg.
>
> Signed-off-by: Nuno Das Neves <nunodasneves@xxxxxxxxxxxxxxxxxxx>
> ---
> arch/x86/include/asm/mshyperv.h | 11 +++++++----
> arch/x86/kernel/cpu/mshyperv.c | 8 ++++----
> 2 files changed, 11 insertions(+), 8 deletions(-)
>
> diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
> index 9ae1a344536b..684c547c1cca 100644
> --- a/arch/x86/include/asm/mshyperv.h
> +++ b/arch/x86/include/asm/mshyperv.h
> @@ -225,10 +225,13 @@ extern bool hv_isolation_type_snp(void);
>
> static inline bool hv_is_synic_reg(unsigned int reg)
> {
> - if ((reg >= HV_REGISTER_SCONTROL) &&
> - (reg <= HV_REGISTER_SINT15))
> - return true;
> - return false;
> + return (reg >= HV_REGISTER_SCONTROL) &&
> + (reg <= HV_REGISTER_SINT15);
> +}
Please put a new line here.
I can fix these issues too if you don't end up sending a new version due
to other issues.
Jinank, please take a look. The code looks sensible to me, but I would
like you to have a look too.
Thanks,
Wei.
> +static inline bool hv_is_sint_reg(unsigned int reg)
> +{
> + return (reg >= HV_REGISTER_SINT0) &&
> + (reg <= HV_REGISTER_SINT15);
> }
>
> u64 hv_get_register(unsigned int reg);
> diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
> index 0ceb6d1f9c3c..6bd344e1200f 100644
> --- a/arch/x86/kernel/cpu/mshyperv.c
> +++ b/arch/x86/kernel/cpu/mshyperv.c
> @@ -44,6 +44,9 @@ struct ms_hyperv_info ms_hyperv;
> #if IS_ENABLED(CONFIG_HYPERV)
> static inline unsigned int hv_get_nested_reg(unsigned int reg)
> {
> + if (hv_is_sint_reg(reg))
> + return reg - HV_REGISTER_SINT0 + HV_REGISTER_NESTED_SINT0;
> +
> switch (reg) {
> case HV_REGISTER_SIMP:
> return HV_REGISTER_NESTED_SIMP;
> @@ -53,8 +56,6 @@ static inline unsigned int hv_get_nested_reg(unsigned int reg)
> return HV_REGISTER_NESTED_SVERSION;
> case HV_REGISTER_SCONTROL:
> return HV_REGISTER_NESTED_SCONTROL;
> - case HV_REGISTER_SINT0:
> - return HV_REGISTER_NESTED_SINT0;
> case HV_REGISTER_EOM:
> return HV_REGISTER_NESTED_EOM;
> default:
> @@ -80,8 +81,7 @@ void hv_set_non_nested_register(unsigned int reg, u64 value)
> hv_ghcb_msr_write(reg, value);
>
> /* Write proxy bit via wrmsl instruction */
> - if (reg >= HV_REGISTER_SINT0 &&
> - reg <= HV_REGISTER_SINT15)
> + if (hv_is_sint_reg(reg))
> wrmsrl(reg, value | 1 << 20);
> } else {
> wrmsrl(reg, value);
> --
> 2.25.1
>