From: Oliver Upton <oupton@google.com>
To: kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu
Cc: Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <seanjc@google.com>,
Marc Zyngier <maz@kernel.org>, Peter Shier <pshier@google.com>,
Jim Mattson <jmattson@google.com>,
David Matlack <dmatlack@google.com>,
Ricardo Koller <ricarkol@google.com>,
Jing Zhang <jingzhangos@google.com>,
Raghavendra Rao Anata <rananta@google.com>,
James Morse <james.morse@arm.com>,
Alexandru Elisei <alexandru.elisei@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
linux-arm-kernel@lists.infradead.org,
Oliver Upton <oupton@google.com>
Subject: [PATCH v3 04/12] tools: arch: x86: pull in pvclock headers
Date: Mon, 19 Jul 2021 18:49:41 +0000 [thread overview]
Message-ID: <20210719184949.1385910-5-oupton@google.com> (raw)
In-Reply-To: <20210719184949.1385910-1-oupton@google.com>
Copy over approximately clean versions of the pvclock headers into
tools. Reconcile headers/symbols missing in tools that are unneeded.
Signed-off-by: Oliver Upton <oupton@google.com>
---
tools/arch/x86/include/asm/pvclock-abi.h | 48 +++++++++++
tools/arch/x86/include/asm/pvclock.h | 103 +++++++++++++++++++++++
2 files changed, 151 insertions(+)
create mode 100644 tools/arch/x86/include/asm/pvclock-abi.h
create mode 100644 tools/arch/x86/include/asm/pvclock.h
diff --git a/tools/arch/x86/include/asm/pvclock-abi.h b/tools/arch/x86/include/asm/pvclock-abi.h
new file mode 100644
index 000000000000..1436226efe3e
--- /dev/null
+++ b/tools/arch/x86/include/asm/pvclock-abi.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_PVCLOCK_ABI_H
+#define _ASM_X86_PVCLOCK_ABI_H
+#ifndef __ASSEMBLY__
+
+/*
+ * These structs MUST NOT be changed.
+ * They are the ABI between hypervisor and guest OS.
+ * Both Xen and KVM are using this.
+ *
+ * pvclock_vcpu_time_info holds the system time and the tsc timestamp
+ * of the last update. So the guest can use the tsc delta to get a
+ * more precise system time. There is one per virtual cpu.
+ *
+ * pvclock_wall_clock references the point in time when the system
+ * time was zero (usually boot time), thus the guest calculates the
+ * current wall clock by adding the system time.
+ *
+ * Protocol for the "version" fields is: hypervisor raises it (making
+ * it uneven) before it starts updating the fields and raises it again
+ * (making it even) when it is done. Thus the guest can make sure the
+ * time values it got are consistent by checking the version before
+ * and after reading them.
+ */
+
+struct pvclock_vcpu_time_info {
+ u32 version;
+ u32 pad0;
+ u64 tsc_timestamp;
+ u64 system_time;
+ u32 tsc_to_system_mul;
+ s8 tsc_shift;
+ u8 flags;
+ u8 pad[2];
+} __attribute__((__packed__)); /* 32 bytes */
+
+struct pvclock_wall_clock {
+ u32 version;
+ u32 sec;
+ u32 nsec;
+} __attribute__((__packed__));
+
+#define PVCLOCK_TSC_STABLE_BIT (1 << 0)
+#define PVCLOCK_GUEST_STOPPED (1 << 1)
+/* PVCLOCK_COUNTS_FROM_ZERO broke ABI and can't be used anymore. */
+#define PVCLOCK_COUNTS_FROM_ZERO (1 << 2)
+#endif /* __ASSEMBLY__ */
+#endif /* _ASM_X86_PVCLOCK_ABI_H */
diff --git a/tools/arch/x86/include/asm/pvclock.h b/tools/arch/x86/include/asm/pvclock.h
new file mode 100644
index 000000000000..2628f9a6330b
--- /dev/null
+++ b/tools/arch/x86/include/asm/pvclock.h
@@ -0,0 +1,103 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_PVCLOCK_H
+#define _ASM_X86_PVCLOCK_H
+
+#include <asm/barrier.h>
+#include <asm/pvclock-abi.h>
+
+/* some helper functions for xen and kvm pv clock sources */
+u64 pvclock_clocksource_read(struct pvclock_vcpu_time_info *src);
+u8 pvclock_read_flags(struct pvclock_vcpu_time_info *src);
+void pvclock_set_flags(u8 flags);
+unsigned long pvclock_tsc_khz(struct pvclock_vcpu_time_info *src);
+void pvclock_resume(void);
+
+void pvclock_touch_watchdogs(void);
+
+static __always_inline
+unsigned pvclock_read_begin(const struct pvclock_vcpu_time_info *src)
+{
+ unsigned version = src->version & ~1;
+ /* Make sure that the version is read before the data. */
+ rmb();
+ return version;
+}
+
+static __always_inline
+bool pvclock_read_retry(const struct pvclock_vcpu_time_info *src,
+ unsigned version)
+{
+ /* Make sure that the version is re-read after the data. */
+ rmb();
+ return version != src->version;
+}
+
+/*
+ * Scale a 64-bit delta by scaling and multiplying by a 32-bit fraction,
+ * yielding a 64-bit result.
+ */
+static inline u64 pvclock_scale_delta(u64 delta, u32 mul_frac, int shift)
+{
+ u64 product;
+#ifdef __i386__
+ u32 tmp1, tmp2;
+#else
+ unsigned long tmp;
+#endif
+
+ if (shift < 0)
+ delta >>= -shift;
+ else
+ delta <<= shift;
+
+#ifdef __i386__
+ __asm__ (
+ "mul %5 ; "
+ "mov %4,%%eax ; "
+ "mov %%edx,%4 ; "
+ "mul %5 ; "
+ "xor %5,%5 ; "
+ "add %4,%%eax ; "
+ "adc %5,%%edx ; "
+ : "=A" (product), "=r" (tmp1), "=r" (tmp2)
+ : "a" ((u32)delta), "1" ((u32)(delta >> 32)), "2" (mul_frac) );
+#elif defined(__x86_64__)
+ __asm__ (
+ "mulq %[mul_frac] ; shrd $32, %[hi], %[lo]"
+ : [lo]"=a"(product),
+ [hi]"=d"(tmp)
+ : "0"(delta),
+ [mul_frac]"rm"((u64)mul_frac));
+#else
+#error implement me!
+#endif
+
+ return product;
+}
+
+static __always_inline
+u64 __pvclock_read_cycles(const struct pvclock_vcpu_time_info *src, u64 tsc)
+{
+ u64 delta = tsc - src->tsc_timestamp;
+ u64 offset = pvclock_scale_delta(delta, src->tsc_to_system_mul,
+ src->tsc_shift);
+ return src->system_time + offset;
+}
+
+struct pvclock_vsyscall_time_info {
+ struct pvclock_vcpu_time_info pvti;
+} __attribute__((__aligned__(64)));
+
+#define PVTI_SIZE sizeof(struct pvclock_vsyscall_time_info)
+
+#ifdef CONFIG_PARAVIRT_CLOCK
+void pvclock_set_pvti_cpu0_va(struct pvclock_vsyscall_time_info *pvti);
+struct pvclock_vsyscall_time_info *pvclock_get_pvti_cpu0_va(void);
+#else
+static inline struct pvclock_vsyscall_time_info *pvclock_get_pvti_cpu0_va(void)
+{
+ return NULL;
+}
+#endif
+
+#endif /* _ASM_X86_PVCLOCK_H */
--
2.32.0.402.g57bb445576-goog
next prev parent reply other threads:[~2021-07-19 21:20 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-19 18:49 [PATCH v3 00/12] KVM: Add idempotent controls for migrating system counter state Oliver Upton
2021-07-19 18:49 ` [PATCH v3 01/12] KVM: x86: Report host tsc and realtime values in KVM_GET_CLOCK Oliver Upton
2021-07-19 18:49 ` [PATCH v3 02/12] KVM: x86: Refactor tsc synchronization code Oliver Upton
2021-07-19 18:49 ` [PATCH v3 03/12] KVM: x86: Expose TSC offset controls to userspace Oliver Upton
2021-07-19 18:49 ` Oliver Upton [this message]
2021-07-19 18:49 ` [PATCH v3 05/12] selftests: KVM: Add test for KVM_{GET,SET}_CLOCK Oliver Upton
2021-07-19 18:49 ` [PATCH v3 06/12] selftests: KVM: Add helpers for vCPU device attributes Oliver Upton
2021-07-19 18:49 ` [PATCH v3 07/12] selftests: KVM: Introduce system counter offset test Oliver Upton
2021-07-19 18:49 ` [PATCH v3 08/12] KVM: arm64: Allow userspace to configure a vCPU's virtual offset Oliver Upton
2021-07-21 16:16 ` Andrew Jones
2021-07-19 18:49 ` [PATCH v3 09/12] selftests: KVM: Add support for aarch64 to system_counter_offset_test Oliver Upton
2021-07-21 16:26 ` Andrew Jones
2021-07-19 18:49 ` [PATCH v3 10/12] KVM: arm64: Provide userspace access to the physical counter offset Oliver Upton
2021-07-21 16:44 ` Andrew Jones
2021-07-19 18:49 ` [PATCH v3 11/12] selftests: KVM: Test physical counter offsetting Oliver Upton
2021-07-21 16:46 ` Andrew Jones
2021-07-19 18:49 ` [PATCH v3 12/12] selftests: KVM: Add counter emulation benchmark Oliver Upton
2021-07-21 18:59 ` Andrew Jones
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