From: Stanislav Kinsburskii <skinsburskii@xxxxxxxxxxxxxxxxxxx> Sent: Thursday, November 3, 2022 10:59 AM
>
> Instead of converting the virtual address to physical directly.
>
> This is a precursor patch for the upcoming support for TSC page mapping into
> Microsoft Hypervisor root partition, where TSC PFN will be defined by the
> hypervisor and thus can't be obtained by linear translation of the physical
> address.
>
> Signed-off-by: Stanislav Kinsburskiy <stanislav.kinsburskiy@xxxxxxxxx>
> CC: Andy Lutomirski <luto@xxxxxxxxxx>
> CC: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> CC: Ingo Molnar <mingo@xxxxxxxxxx>
> CC: Borislav Petkov <bp@xxxxxxxxx>
> CC: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> CC: x86@xxxxxxxxxx
> CC: "H. Peter Anvin" <hpa@xxxxxxxxx>
> CC: "K. Y. Srinivasan" <kys@xxxxxxxxxxxxx>
> CC: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx>
> CC: Wei Liu <wei.liu@xxxxxxxxxx>
> CC: Dexuan Cui <decui@xxxxxxxxxxxxx>
> CC: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
> CC: linux-kernel@xxxxxxxxxxxxxxx
> CC: linux-hyperv@xxxxxxxxxxxxxxx
> ---
> arch/x86/entry/vdso/vma.c | 7 +++----
> drivers/clocksource/hyperv_timer.c | 3 ++-
> include/clocksource/hyperv_timer.h | 6 ++++++
> 3 files changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
> index 311eae30e089..6976416b2c9f 100644
> --- a/arch/x86/entry/vdso/vma.c
> +++ b/arch/x86/entry/vdso/vma.c
> @@ -210,11 +210,10 @@ static vm_fault_t vvar_fault(const struct
> vm_special_mapping *sm,
> pgprot_decrypted(vma->vm_page_prot));
> }
> } else if (sym_offset == image->sym_hvclock_page) {
> - struct ms_hyperv_tsc_page *tsc_pg = hv_get_tsc_page();
> + pfn = hv_get_tsc_pfn();
>
> - if (tsc_pg && vclock_was_used(VDSO_CLOCKMODE_HVCLOCK))
> - return vmf_insert_pfn(vma, vmf->address,
> - virt_to_phys(tsc_pg) >> PAGE_SHIFT);
> + if (pfn && vclock_was_used(VDSO_CLOCKMODE_HVCLOCK))
> + return vmf_insert_pfn(vma, vmf->address, pfn);
> } else if (sym_offset == image->sym_timens_page) {
> struct page *timens_page = find_timens_vvar_page(vma);
>
> diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
> index b7af19d06b51..9445a1558fe9 100644
> --- a/drivers/clocksource/hyperv_timer.c
> +++ b/drivers/clocksource/hyperv_timer.c
> @@ -370,10 +370,11 @@ static union {
> static struct ms_hyperv_tsc_page *tsc_page = &tsc_pg.page;
> static unsigned long tsc_pfn;
>
> -static unsigned long hv_get_tsc_pfn(void)
> +unsigned long hv_get_tsc_pfn(void)
> {
> return tsc_pfn;
> }
> +EXPORT_SYMBOL_GPL(hv_get_tsc_pfn);
>
> struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
> {
> diff --git a/include/clocksource/hyperv_timer.h
> b/include/clocksource/hyperv_timer.h
> index b3f5d73ae1d6..3078d23faaea 100644
> --- a/include/clocksource/hyperv_timer.h
> +++ b/include/clocksource/hyperv_timer.h
> @@ -32,6 +32,7 @@ extern void hv_stimer0_isr(void);
>
> extern void hv_init_clocksource(void);
>
> +extern unsigned long hv_get_tsc_pfn(void);
> extern struct ms_hyperv_tsc_page *hv_get_tsc_page(void);
>
> static inline notrace u64
> @@ -90,6 +91,11 @@ hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg)
> }
>
> #else /* CONFIG_HYPERV_TIMER */
> +static inline unsigned long hv_get_tsc_pfn(void)
> +{
> + return 0;
> +}
> +
> static inline struct ms_hyperv_tsc_page *hv_get_tsc_page(void)
> {
> return NULL;
>
Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx>
