From e5dfd093eca01a5d8d967f959a2372d7d82eb59c Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 13 Nov 2022 22:21:15 +0100 Subject: clocksource/drivers/hyper-v: Include asm/hyperv-tlfs.h not asm/mshyperv.h clocksource/hyperv_timer.h is included into the VDSO build. It includes asm/mshyperv.h which in turn includes the world and some more. This worked so far by chance, but any subtle change in the include chain results in a build breakage because VDSO builds are building user space libraries. Include asm/hyperv-tlfs.h instead which contains everything what the VDSO build needs except the hv_get_raw_timer() define. Move this define into a separate header file, which contains the prerequisites (msr.h) and is included by clocksource/hyperv_timer.h. Fixup drivers/hv/vmbus_drv.c which relies on the indirect include of asm/mshyperv.h. With that the VDSO build only pulls in the minimum requirements. Signed-off-by: Thomas Gleixner Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/87fsemtut0.ffs@tglx --- include/clocksource/hyperv_timer.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'include/clocksource/hyperv_timer.h') diff --git a/include/clocksource/hyperv_timer.h b/include/clocksource/hyperv_timer.h index b3f5d73ae1d6..b4a3935801ca 100644 --- a/include/clocksource/hyperv_timer.h +++ b/include/clocksource/hyperv_timer.h @@ -15,13 +15,15 @@ #include #include -#include +#include #define HV_MAX_MAX_DELTA_TICKS 0xffffffff #define HV_MIN_DELTA_TICKS 1 #ifdef CONFIG_HYPERV_TIMER +#include + /* Routines called by the VMbus driver */ extern int hv_stimer_alloc(bool have_percpu_irqs); extern int hv_stimer_cleanup(unsigned int cpu); -- cgit v1.2.3 From 364adc45e9aff8cc08d7b87b6e61f6f272f70308 Mon Sep 17 00:00:00 2001 From: Stanislav Kinsburskiy Date: Thu, 3 Nov 2022 17:58:59 +0000 Subject: clocksource: hyper-v: Use TSC PFN getter to map vvar page 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 CC: Andy Lutomirski CC: Thomas Gleixner CC: Ingo Molnar CC: Borislav Petkov CC: Dave Hansen CC: x86@kernel.org CC: "H. Peter Anvin" CC: "K. Y. Srinivasan" CC: Haiyang Zhang CC: Wei Liu CC: Dexuan Cui CC: Daniel Lezcano CC: linux-kernel@vger.kernel.org CC: linux-hyperv@vger.kernel.org Reviewed-by: Michael Kelley Reviewed-by: Anirudh Rayabharam Link: https://lore.kernel.org/r/166749833939.218190.14095015146003109462.stgit@skinsburskii-cloud-desktop.internal.cloudapp.net Signed-off-by: Wei Liu --- 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(-) (limited to 'include/clocksource/hyperv_timer.h') 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; -- cgit v1.2.3 From 0408f16b43e578e70ad12a857159a0a771cfaa7c Mon Sep 17 00:00:00 2001 From: Stanislav Kinsburskiy Date: Fri, 4 Nov 2022 20:40:55 +0000 Subject: clocksource: hyper-v: Add TSC page support for root partition Microsoft Hypervisor root partition has to map the TSC page specified by the hypervisor, instead of providing the page to the hypervisor like it's done in the guest partitions. However, it's too early to map the page when the clock is initialized, so, the actual mapping is happening later. Signed-off-by: Stanislav Kinsburskiy CC: "K. Y. Srinivasan" CC: Haiyang Zhang CC: Wei Liu CC: Dexuan Cui CC: Thomas Gleixner CC: Ingo Molnar CC: Borislav Petkov CC: Dave Hansen CC: x86@kernel.org CC: "H. Peter Anvin" CC: Daniel Lezcano CC: linux-hyperv@vger.kernel.org CC: linux-kernel@vger.kernel.org Reviewed-by: Michael Kelley Reviewed-by: Anirudh Rayabharam Link: https://lore.kernel.org/r/166759443644.385891.15921594265843430260.stgit@skinsburskii-cloud-desktop.internal.cloudapp.net Signed-off-by: Wei Liu --- arch/x86/hyperv/hv_init.c | 2 ++ drivers/clocksource/hyperv_timer.c | 44 ++++++++++++++++++++++++++++++-------- include/clocksource/hyperv_timer.h | 1 + 3 files changed, 38 insertions(+), 9 deletions(-) (limited to 'include/clocksource/hyperv_timer.h') diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c index a269049a43ce..a823fde1ad7f 100644 --- a/arch/x86/hyperv/hv_init.c +++ b/arch/x86/hyperv/hv_init.c @@ -462,6 +462,8 @@ void __init hyperv_init(void) BUG_ON(!src); memcpy_to_page(pg, 0, src, HV_HYP_PAGE_SIZE); memunmap(src); + + hv_remap_tsc_clocksource(); } else { hypercall_msr.guest_physical_address = vmalloc_to_pfn(hv_hypercall_pg); wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c index 9445a1558fe9..c0cef92b12b8 100644 --- a/drivers/clocksource/hyperv_timer.c +++ b/drivers/clocksource/hyperv_timer.c @@ -509,9 +509,6 @@ static bool __init hv_init_tsc_clocksource(void) if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE)) return false; - if (hv_root_partition) - return false; - /* * If Hyper-V offers TSC_INVARIANT, then the virtualized TSC correctly * handles frequency and offset changes due to live migration, @@ -529,16 +526,28 @@ static bool __init hv_init_tsc_clocksource(void) } hv_read_reference_counter = read_hv_clock_tsc; - tsc_pfn = HVPFN_DOWN(virt_to_phys(tsc_page)); /* - * The Hyper-V TLFS specifies to preserve the value of reserved - * bits in registers. So read the existing value, preserve the - * low order 12 bits, and add in the guest physical address - * (which already has at least the low 12 bits set to zero since - * it is page aligned). Also set the "enable" bit, which is bit 0. + * TSC page mapping works differently in root compared to guest. + * - In guest partition the guest PFN has to be passed to the + * hypervisor. + * - In root partition it's other way around: it has to map the PFN + * provided by the hypervisor. + * But it can't be mapped right here as it's too early and MMU isn't + * ready yet. So, we only set the enable bit here and will remap the + * page later in hv_remap_tsc_clocksource(). + * + * It worth mentioning, that TSC clocksource read function + * (read_hv_clock_tsc) has a MSR-based fallback mechanism, used when + * TSC page is zeroed (which is the case until the PFN is remapped) and + * thus TSC clocksource will work even without the real TSC page + * mapped. */ tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC); + if (hv_root_partition) + tsc_pfn = tsc_msr.pfn; + else + tsc_pfn = HVPFN_DOWN(virt_to_phys(tsc_page)); tsc_msr.enable = 1; tsc_msr.pfn = tsc_pfn; hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64); @@ -573,3 +582,20 @@ void __init hv_init_clocksource(void) hv_sched_clock_offset = hv_read_reference_counter(); hv_setup_sched_clock(read_hv_sched_clock_msr); } + +void __init hv_remap_tsc_clocksource(void) +{ + if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE)) + return; + + if (!hv_root_partition) { + WARN(1, "%s: attempt to remap TSC page in guest partition\n", + __func__); + return; + } + + tsc_page = memremap(tsc_pfn << HV_HYP_PAGE_SHIFT, sizeof(tsc_pg), + MEMREMAP_WB); + if (!tsc_page) + pr_err("Failed to remap Hyper-V TSC page.\n"); +} diff --git a/include/clocksource/hyperv_timer.h b/include/clocksource/hyperv_timer.h index 3078d23faaea..783701a2102d 100644 --- a/include/clocksource/hyperv_timer.h +++ b/include/clocksource/hyperv_timer.h @@ -31,6 +31,7 @@ extern void hv_stimer_global_cleanup(void); extern void hv_stimer0_isr(void); extern void hv_init_clocksource(void); +extern void hv_remap_tsc_clocksource(void); extern unsigned long hv_get_tsc_pfn(void); extern struct ms_hyperv_tsc_page *hv_get_tsc_page(void); -- cgit v1.2.3