From 3dc4f7cfb7441e5e0fed3a02fc81cdaabd28300a Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Tue, 27 Nov 2012 23:28:56 -0200 Subject: [PATCH] x86: kvm guest: pvclock vsyscall support Hook into generic pvclock vsyscall code, with the aim to allow userspace to have visibility into pvclock data. Signed-off-by: Marcelo Tosatti --- arch/x86/include/asm/kvm_guest.h | 6 ++++ arch/x86/kernel/kvm.c | 13 ++++++++ arch/x86/kernel/kvmclock.c | 54 +++++++++++++++++++++++++------- 3 files changed, 61 insertions(+), 12 deletions(-) create mode 100644 arch/x86/include/asm/kvm_guest.h diff --git a/arch/x86/include/asm/kvm_guest.h b/arch/x86/include/asm/kvm_guest.h new file mode 100644 index 00000000000..a92b1763c41 --- /dev/null +++ b/arch/x86/include/asm/kvm_guest.h @@ -0,0 +1,6 @@ +#ifndef _ASM_X86_KVM_GUEST_H +#define _ASM_X86_KVM_GUEST_H + +int kvm_setup_vsyscall_timeinfo(void); + +#endif /* _ASM_X86_KVM_GUEST_H */ diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 4180a874c76..a91c6b482b4 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -42,6 +42,7 @@ #include #include #include +#include static int kvmapf = 1; @@ -62,6 +63,15 @@ static int parse_no_stealacc(char *arg) early_param("no-steal-acc", parse_no_stealacc); +static int kvmclock_vsyscall = 1; +static int parse_no_kvmclock_vsyscall(char *arg) +{ + kvmclock_vsyscall = 0; + return 0; +} + +early_param("no-kvmclock-vsyscall", parse_no_kvmclock_vsyscall); + static DEFINE_PER_CPU(struct kvm_vcpu_pv_apf_data, apf_reason) __aligned(64); static DEFINE_PER_CPU(struct kvm_steal_time, steal_time) __aligned(64); static int has_steal_clock = 0; @@ -471,6 +481,9 @@ void __init kvm_guest_init(void) if (kvm_para_has_feature(KVM_FEATURE_PV_EOI)) apic_set_eoi_write(kvm_guest_apic_eoi_write); + if (kvmclock_vsyscall) + kvm_setup_vsyscall_timeinfo(); + #ifdef CONFIG_SMP smp_ops.smp_prepare_boot_cpu = kvm_smp_prepare_boot_cpu; register_cpu_notifier(&kvm_cpu_notifier); diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c index c7d75678886..220a360010f 100644 --- a/arch/x86/kernel/kvmclock.c +++ b/arch/x86/kernel/kvmclock.c @@ -40,11 +40,7 @@ static int parse_no_kvmclock(char *arg) early_param("no-kvmclock", parse_no_kvmclock); /* The hypervisor will put information about time periodically here */ -struct pvclock_aligned_vcpu_time_info { - struct pvclock_vcpu_time_info clock; -} __attribute__((__aligned__(SMP_CACHE_BYTES))); - -static struct pvclock_aligned_vcpu_time_info *hv_clock; +static struct pvclock_vsyscall_time_info *hv_clock; static struct pvclock_wall_clock wall_clock; /* @@ -67,7 +63,7 @@ static unsigned long kvm_get_wallclock(void) preempt_disable(); cpu = smp_processor_id(); - vcpu_time = &hv_clock[cpu].clock; + vcpu_time = &hv_clock[cpu].pvti; pvclock_read_wallclock(&wall_clock, vcpu_time, &ts); preempt_enable(); @@ -88,7 +84,7 @@ static cycle_t kvm_clock_read(void) preempt_disable_notrace(); cpu = smp_processor_id(); - src = &hv_clock[cpu].clock; + src = &hv_clock[cpu].pvti; ret = pvclock_clocksource_read(src); preempt_enable_notrace(); return ret; @@ -116,7 +112,7 @@ static unsigned long kvm_get_tsc_khz(void) preempt_disable(); cpu = smp_processor_id(); - src = &hv_clock[cpu].clock; + src = &hv_clock[cpu].pvti; tsc_khz = pvclock_tsc_khz(src); preempt_enable(); return tsc_khz; @@ -143,7 +139,7 @@ bool kvm_check_and_clear_guest_paused(void) if (!hv_clock) return ret; - src = &hv_clock[cpu].clock; + src = &hv_clock[cpu].pvti; if ((src->flags & PVCLOCK_GUEST_STOPPED) != 0) { src->flags &= ~PVCLOCK_GUEST_STOPPED; ret = true; @@ -164,7 +160,7 @@ int kvm_register_clock(char *txt) { int cpu = smp_processor_id(); int low, high, ret; - struct pvclock_vcpu_time_info *src = &hv_clock[cpu].clock; + struct pvclock_vcpu_time_info *src = &hv_clock[cpu].pvti; low = (int)__pa(src) | 1; high = ((u64)__pa(src) >> 32); @@ -235,7 +231,7 @@ void __init kvmclock_init(void) printk(KERN_INFO "kvm-clock: Using msrs %x and %x", msr_kvm_system_time, msr_kvm_wall_clock); - mem = memblock_alloc(sizeof(struct pvclock_aligned_vcpu_time_info) * NR_CPUS, + mem = memblock_alloc(sizeof(struct pvclock_vsyscall_time_info)*NR_CPUS, PAGE_SIZE); if (!mem) return; @@ -244,7 +240,7 @@ void __init kvmclock_init(void) if (kvm_register_clock("boot clock")) { hv_clock = NULL; memblock_free(mem, - sizeof(struct pvclock_aligned_vcpu_time_info)*NR_CPUS); + sizeof(struct pvclock_vsyscall_time_info)*NR_CPUS); return; } pv_time_ops.sched_clock = kvm_clock_read; @@ -269,3 +265,37 @@ void __init kvmclock_init(void) if (kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE_STABLE_BIT)) pvclock_set_flags(PVCLOCK_TSC_STABLE_BIT); } + +int __init kvm_setup_vsyscall_timeinfo(void) +{ +#ifdef CONFIG_X86_64 + int cpu; + int ret; + u8 flags; + struct pvclock_vcpu_time_info *vcpu_time; + unsigned int size; + + size = sizeof(struct pvclock_vsyscall_time_info)*NR_CPUS; + + preempt_disable(); + cpu = smp_processor_id(); + + vcpu_time = &hv_clock[cpu].pvti; + flags = pvclock_read_flags(vcpu_time); + + if (!(flags & PVCLOCK_TSC_STABLE_BIT)) { + preempt_enable(); + return 1; + } + + if ((ret = pvclock_init_vsyscall(hv_clock, size))) { + preempt_enable(); + return ret; + } + + preempt_enable(); + + kvm_clock.archdata.vclock_mode = VCLOCK_PVCLOCK; +#endif + return 0; +}