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[Xen-changelog] [xen-unstable] Scaling guest's TSC when the target machine's frequency is different

From: Xen patchbot-unstable <patchbot-unstable@xxxxxxxxxxxxxxxxxxx>

Date: Fri, 26 Jun 2009 08:56:01 -0700

Delivery-date: Fri, 26 Jun 2009 09:04:00 -0700

List-id: BK change log <xen-changelog.lists.xensource.com>

# HG changeset patch # User Keir Fraser <keir.fraser@xxxxxxxxxx> # Date 1245837922 -3600 # Node ID 81edfffb3aff92e03acd5ed68477763eb438c9ae # Parent 50634c215234e15dc8f4b324d9ee3b5fad779c34 Scaling guest's TSC when the target machine's frequency is different with its requirement. Using trap&emulate for guest's each rdtsc instruction first, maybe it can be optimized later. Signed-off-by: Xiantao Zhang <xiantao.zhang@xxxxxxxxx> --- xen/arch/x86/hvm/hvm.c | 65 +++++++++++++++++++++++++++++++-------- xen/arch/x86/hvm/save.c | 9 +++++ xen/arch/x86/hvm/vmx/vmx.c | 11 ++++++ xen/arch/x86/hvm/vpt.c | 3 + xen/include/asm-x86/hvm/domain.h | 2 - xen/include/asm-x86/hvm/hvm.h | 4 ++ 6 files changed, 79 insertions(+), 15 deletions(-) diff -r 50634c215234 -r 81edfffb3aff xen/arch/x86/hvm/hvm.c --- a/xen/arch/x86/hvm/hvm.c Wed Jun 24 10:57:00 2009 +0100 +++ b/xen/arch/x86/hvm/hvm.c Wed Jun 24 11:05:22 2009 +0100 @@ -144,26 +144,67 @@ uint8_t hvm_combine_hw_exceptions(uint8_ return TRAP_double_fault; } +void hvm_enable_rdtsc_exiting(struct domain *d) +{ + struct vcpu *v; + + if ( opt_softtsc || !hvm_funcs.enable_rdtsc_exiting ) + return; + + for_each_vcpu ( d, v ) + hvm_funcs.enable_rdtsc_exiting(v); +} + +int hvm_gtsc_need_scale(struct domain *d) +{ + uint32_t gtsc_mhz, htsc_mhz; + + gtsc_mhz = d->arch.hvm_domain.gtsc_khz / 1000; + htsc_mhz = opt_softtsc ? 1000 : ((uint32_t)cpu_khz / 1000); + + d->arch.hvm_domain.tsc_scaled = (gtsc_mhz && (gtsc_mhz != htsc_mhz)); + return d->arch.hvm_domain.tsc_scaled; +} + +static u64 hvm_h2g_scale_tsc(struct vcpu *v, u64 host_tsc) +{ + uint32_t gtsc_khz, htsc_khz; + + if ( !v->domain->arch.hvm_domain.tsc_scaled ) + return host_tsc; + + htsc_khz = opt_softtsc ? 1000000 : cpu_khz; + gtsc_khz = v->domain->arch.hvm_domain.gtsc_khz; + return muldiv64(host_tsc, gtsc_khz, htsc_khz); +} + void hvm_set_guest_tsc(struct vcpu *v, u64 guest_tsc) { - u64 host_tsc; - - rdtscll(host_tsc); - - v->arch.hvm_vcpu.cache_tsc_offset = guest_tsc - host_tsc; - hvm_funcs.set_tsc_offset(v, v->arch.hvm_vcpu.cache_tsc_offset); -} - -u64 hvm_get_guest_tsc(struct vcpu *v) -{ - u64 host_tsc; + uint64_t host_tsc, scaled_htsc; if ( opt_softtsc ) host_tsc = hvm_get_guest_time(v); else rdtscll(host_tsc); - return host_tsc + v->arch.hvm_vcpu.cache_tsc_offset; + scaled_htsc = hvm_h2g_scale_tsc(v, host_tsc); + + v->arch.hvm_vcpu.cache_tsc_offset = guest_tsc - scaled_htsc; + hvm_funcs.set_tsc_offset(v, v->arch.hvm_vcpu.cache_tsc_offset); +} + +u64 hvm_get_guest_tsc(struct vcpu *v) +{ + uint64_t host_tsc, scaled_htsc; + + if ( opt_softtsc ) + host_tsc = hvm_get_guest_time(v); + else + rdtscll(host_tsc); + + scaled_htsc = hvm_h2g_scale_tsc(v, host_tsc); + + return scaled_htsc + v->arch.hvm_vcpu.cache_tsc_offset; } void hvm_migrate_timers(struct vcpu *v) diff -r 50634c215234 -r 81edfffb3aff xen/arch/x86/hvm/save.c --- a/xen/arch/x86/hvm/save.c Wed Jun 24 10:57:00 2009 +0100 +++ b/xen/arch/x86/hvm/save.c Wed Jun 24 11:05:22 2009 +0100 @@ -63,6 +63,15 @@ int arch_hvm_load(struct domain *d, stru /* Restore guest's preferred TSC frequency. */ d->arch.hvm_domain.gtsc_khz = hdr->gtsc_khz; + if ( hdr->gtsc_khz && hvm_gtsc_need_scale(d) ) + { + hvm_enable_rdtsc_exiting(d); + gdprintk(XENLOG_WARNING, "Loading VM(id:%d) expects freq: %dmHz, " + "but host's freq :%"PRIu64"mHz, trap and emulate rdtsc!!!\n", + d->domain_id, hdr->gtsc_khz / 1000, opt_softtsc ? 1000 : + cpu_khz / 1000); + } + /* VGA state is not saved/restored, so we nobble the cache. */ d->arch.hvm_domain.stdvga.cache = 0; diff -r 50634c215234 -r 81edfffb3aff xen/arch/x86/hvm/vmx/vmx.c --- a/xen/arch/x86/hvm/vmx/vmx.c Wed Jun 24 10:57:00 2009 +0100 +++ b/xen/arch/x86/hvm/vmx/vmx.c Wed Jun 24 11:05:22 2009 +0100 @@ -947,6 +947,14 @@ static void vmx_set_tsc_offset(struct vc vmx_vmcs_exit(v); } +static void vmx_enable_rdtsc_exiting(struct vcpu *v) +{ + vmx_vmcs_enter(v); + v->arch.hvm_vmx.exec_control |= CPU_BASED_RDTSC_EXITING; + __vmwrite(CPU_BASED_VM_EXEC_CONTROL, v->arch.hvm_vmx.exec_control); + vmx_vmcs_exit(v); + } + void do_nmi(struct cpu_user_regs *); static void vmx_init_hypercall_page(struct domain *d, void *hypercall_page) @@ -1395,7 +1403,8 @@ static struct hvm_function_table vmx_fun .msr_write_intercept = vmx_msr_write_intercept, .invlpg_intercept = vmx_invlpg_intercept, .set_uc_mode = vmx_set_uc_mode, - .set_info_guest = vmx_set_info_guest + .set_info_guest = vmx_set_info_guest, + .enable_rdtsc_exiting = vmx_enable_rdtsc_exiting }; static unsigned long *vpid_bitmap; diff -r 50634c215234 -r 81edfffb3aff xen/arch/x86/hvm/vpt.c --- a/xen/arch/x86/hvm/vpt.c Wed Jun 24 10:57:00 2009 +0100 +++ b/xen/arch/x86/hvm/vpt.c Wed Jun 24 11:05:22 2009 +0100 @@ -33,7 +33,8 @@ void hvm_init_guest_time(struct domain * pl->stime_offset = -(u64)get_s_time(); pl->last_guest_time = 0; - d->arch.hvm_domain.gtsc_khz = cpu_khz; + d->arch.hvm_domain.gtsc_khz = opt_softtsc ? 1000000 : cpu_khz; + d->arch.hvm_domain.tsc_scaled = 0; } u64 hvm_get_guest_time(struct vcpu *v) diff -r 50634c215234 -r 81edfffb3aff xen/include/asm-x86/hvm/domain.h --- a/xen/include/asm-x86/hvm/domain.h Wed Jun 24 10:57:00 2009 +0100 +++ b/xen/include/asm-x86/hvm/domain.h Wed Jun 24 11:05:22 2009 +0100 @@ -45,7 +45,7 @@ struct hvm_domain { struct hvm_ioreq_page buf_ioreq; uint32_t gtsc_khz; /* kHz */ - uint32_t pad0; + bool_t tsc_scaled; struct pl_time pl_time; struct hvm_io_handler io_handler; diff -r 50634c215234 -r 81edfffb3aff xen/include/asm-x86/hvm/hvm.h --- a/xen/include/asm-x86/hvm/hvm.h Wed Jun 24 10:57:00 2009 +0100 +++ b/xen/include/asm-x86/hvm/hvm.h Wed Jun 24 11:05:22 2009 +0100 @@ -129,6 +129,7 @@ struct hvm_function_table { void (*invlpg_intercept)(unsigned long vaddr); void (*set_uc_mode)(struct vcpu *v); void (*set_info_guest)(struct vcpu *v); + void (*enable_rdtsc_exiting)(struct vcpu *v); }; extern struct hvm_function_table hvm_funcs; @@ -282,6 +283,9 @@ int hvm_event_needs_reinjection(uint8_t uint8_t hvm_combine_hw_exceptions(uint8_t vec1, uint8_t vec2); +void hvm_enable_rdtsc_exiting(struct domain *d); +int hvm_gtsc_need_scale(struct domain *d); + static inline int hvm_cpu_up(void) { if ( hvm_funcs.cpu_up ) _______________________________________________ Xen-changelog mailing list Xen-changelog@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-changelog

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