From: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
To: kys@microsoft.com, haiyangz@microsoft.com,
sthemmin@microsoft.com, wei.liu@kernel.org, decui@microsoft.com,
tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com,
daniel.lezcano@linaro.org, Arnd Bergmann <arnd@arndb.de>,
linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arch@vger.kernel.org
Cc: Anirudh Rayabharam <anrayabh@linux.microsoft.com>,
kumarpraveen@linux.microsoft.com, mail@anirudhrb.com
Subject: [PATCH 2/2] clocksource/drivers/hyperv: add data structure for reference TSC MSR
Date: Wed, 26 Oct 2022 19:17:15 +0530 [thread overview]
Message-ID: <20221026134715.1438789-3-anrayabh@linux.microsoft.com> (raw)
In-Reply-To: <20221026134715.1438789-1-anrayabh@linux.microsoft.com>
Add a data structure to represent the reference TSC MSR similar to
other MSRs. This simplifies the code for updating the MSR.
Signed-off-by: Anirudh Rayabharam <anrayabh@linux.microsoft.com>
---
arch/x86/hyperv/hv_init.c | 10 +++++-----
drivers/clocksource/hyperv_timer.c | 28 ++++++++++++++--------------
include/asm-generic/hyperv-tlfs.h | 9 +++++++++
3 files changed, 28 insertions(+), 19 deletions(-)
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 76ff63d69461..78993148d14c 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -537,7 +537,7 @@ void __init hyperv_init(void)
void hyperv_cleanup(void)
{
union hv_x64_msr_hypercall_contents hypercall_msr;
- u64 tsc_msr;
+ union hv_reference_tsc_msr tsc_msr;
unregister_syscore_ops(&hv_syscore_ops);
@@ -557,10 +557,10 @@ void hyperv_cleanup(void)
hypercall_msr.enable = 0;
wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
- /* Reset the TSC page */
- rdmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr);
- tsc_msr &= ~BIT_ULL(0);
- wrmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr);
+ /* Reset the TSC page. */
+ rdmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
+ tsc_msr.enable = 0;
+ wrmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
}
void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die)
diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
index bb47610bbd1c..11332c82d1af 100644
--- a/drivers/clocksource/hyperv_timer.c
+++ b/drivers/clocksource/hyperv_timer.c
@@ -395,25 +395,25 @@ static u64 notrace read_hv_sched_clock_tsc(void)
static void suspend_hv_clock_tsc(struct clocksource *arg)
{
- u64 tsc_msr;
+ union hv_reference_tsc_msr tsc_msr;
/* Disable the TSC page */
- tsc_msr = hv_get_register(HV_REGISTER_REFERENCE_TSC);
- tsc_msr &= ~BIT_ULL(0);
- hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr);
+ tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC);
+ tsc_msr.enable = 0;
+ hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64);
}
static void resume_hv_clock_tsc(struct clocksource *arg)
{
phys_addr_t phys_addr = virt_to_phys(&tsc_pg);
- u64 tsc_msr;
+ union hv_reference_tsc_msr tsc_msr;
/* Re-enable the TSC page */
- tsc_msr = hv_get_register(HV_REGISTER_REFERENCE_TSC);
- tsc_msr &= GENMASK_ULL(11, 0);
- tsc_msr |= BIT_ULL(0) | (u64)phys_addr;
- hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr);
+ tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC);
+ tsc_msr.enable = 1;
+ tsc_msr.pfn = __phys_to_pfn(phys_addr);
+ hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64);
}
#ifdef HAVE_VDSO_CLOCKMODE_HVCLOCK
@@ -495,7 +495,7 @@ static __always_inline void hv_setup_sched_clock(void *sched_clock) {}
static bool __init hv_init_tsc_clocksource(void)
{
- u64 tsc_msr;
+ union hv_reference_tsc_msr tsc_msr;
phys_addr_t phys_addr;
if (!(ms_hyperv.features & HV_MSR_REFERENCE_TSC_AVAILABLE))
@@ -530,10 +530,10 @@ static bool __init hv_init_tsc_clocksource(void)
* (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_msr = hv_get_register(HV_REGISTER_REFERENCE_TSC);
- tsc_msr &= GENMASK_ULL(11, 0);
- tsc_msr = tsc_msr | 0x1 | (u64)phys_addr;
- hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr);
+ tsc_msr.as_uint64 = hv_get_register(HV_REGISTER_REFERENCE_TSC);
+ tsc_msr.enable = 1;
+ tsc_msr.pfn = __phys_to_pfn(phys_addr);
+ hv_set_register(HV_REGISTER_REFERENCE_TSC, tsc_msr.as_uint64);
clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);
diff --git a/include/asm-generic/hyperv-tlfs.h b/include/asm-generic/hyperv-tlfs.h
index fdce7a4cfc6f..b17c6eeb9afa 100644
--- a/include/asm-generic/hyperv-tlfs.h
+++ b/include/asm-generic/hyperv-tlfs.h
@@ -102,6 +102,15 @@ struct ms_hyperv_tsc_page {
volatile s64 tsc_offset;
} __packed;
+union hv_reference_tsc_msr {
+ u64 as_uint64;
+ struct {
+ u64 enable:1;
+ u64 reserved:11;
+ u64 pfn:52;
+ } __packed;
+};
+
/*
* The guest OS needs to register the guest ID with the hypervisor.
* The guest ID is a 64 bit entity and the structure of this ID is
--
2.34.1
next prev parent reply other threads:[~2022-10-26 13:49 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-26 13:47 [PATCH 0/2] Fix MSR access errors during kexec in root partition Anirudh Rayabharam
2022-10-26 13:47 ` [PATCH 1/2] x86/hyperv: fix invalid writes to MSRs during root partition kexec Anirudh Rayabharam
2022-10-26 14:58 ` Michael Kelley (LINUX)
2022-10-27 10:01 ` Anirudh Rayabharam
2022-10-26 13:47 ` Anirudh Rayabharam [this message]
2022-10-26 14:57 ` [PATCH 0/2] Fix MSR access errors during kexec in root partition Michael Kelley (LINUX)
2022-10-27 10:03 ` Anirudh Rayabharam
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