From 500065393400fc88d20c6d655717c00efc07dc52 Mon Sep 17 00:00:00 2001 From: Oliver Upton Date: Thu, 16 Sep 2021 18:15:47 +0000 Subject: tools: arch: x86: pull in pvclock headers 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 Message-Id: <20210916181555.973085-2-oupton@google.com> Signed-off-by: Paolo Bonzini --- 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 (limited to 'tools/arch') 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 +#include + +/* 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 */ -- cgit