From 629b5348841a10afce49fbe81619863fd839f217 Mon Sep 17 00:00:00 2001 From: Joao Martins Date: Thu, 28 Jun 2018 15:06:43 -0400 Subject: [PATCH] KVM: x86/xen: update wallclock region Wallclock on Xen is written in the shared_info page. To that purpose, export kvm_write_wall_clock() and pass on the GPA of its location to populate the shared_info wall clock data. Signed-off-by: Joao Martins Signed-off-by: David Woodhouse --- arch/x86/kvm/x86.c | 17 ++++++++++++----- arch/x86/kvm/x86.h | 1 + arch/x86/kvm/xen.c | 33 ++++++++++++++++++++++++++++++--- 3 files changed, 43 insertions(+), 8 deletions(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 59bcba1..040d3d4 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1949,15 +1949,14 @@ static s64 get_kvmclock_base_ns(void) } #endif -static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock) +void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock, int sec_hi_ofs) { int version; int r; struct pvclock_wall_clock wc; + u32 wc_sec_hi; u64 wall_nsec; - kvm->arch.wall_clock = wall_clock; - if (!wall_clock) return; @@ -1986,6 +1985,12 @@ static void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock) kvm_write_guest(kvm, wall_clock, &wc, sizeof(wc)); + if (sec_hi_ofs) { + wc_sec_hi = wall_nsec >> 32; + kvm_write_guest(kvm, wall_clock + sec_hi_ofs, + &wc_sec_hi, sizeof(wc_sec_hi)); + } + version++; kvm_write_guest(kvm, wall_clock, &version, sizeof(version)); } @@ -3131,13 +3136,15 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) if (!guest_pv_has(vcpu, KVM_FEATURE_CLOCKSOURCE2)) return 1; - kvm_write_wall_clock(vcpu->kvm, data); + vcpu->kvm->arch.wall_clock = data; + kvm_write_wall_clock(vcpu->kvm, data, 0); break; case MSR_KVM_WALL_CLOCK: if (!guest_pv_has(vcpu, KVM_FEATURE_CLOCKSOURCE)) return 1; - kvm_write_wall_clock(vcpu->kvm, data); + vcpu->kvm->arch.wall_clock = data; + kvm_write_wall_clock(vcpu->kvm, data, 0); break; case MSR_KVM_SYSTEM_TIME_NEW: if (!guest_pv_has(vcpu, KVM_FEATURE_CLOCKSOURCE2)) diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h index cc652a3..39eb048 100644 --- a/arch/x86/kvm/x86.h +++ b/arch/x86/kvm/x86.h @@ -247,6 +247,7 @@ static inline bool kvm_vcpu_latch_init(struct kvm_vcpu *vcpu) return is_smm(vcpu) || static_call(kvm_x86_apic_init_signal_blocked)(vcpu); } +void kvm_write_wall_clock(struct kvm *kvm, gpa_t wall_clock, int sec_hi_ofs); void kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip); void kvm_write_tsc(struct kvm_vcpu *vcpu, struct msr_data *msr); diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c index 924d4e8..eab4dce 100644 --- a/arch/x86/kvm/xen.c +++ b/arch/x86/kvm/xen.c @@ -21,15 +21,42 @@ DEFINE_STATIC_KEY_DEFERRED_FALSE(kvm_xen_enabled, HZ); static int kvm_xen_shared_info_init(struct kvm *kvm, gfn_t gfn) { + gpa_t gpa = gfn_to_gpa(gfn); + int wc_ofs, sec_hi_ofs; int ret; int idx = srcu_read_lock(&kvm->srcu); ret = kvm_gfn_to_hva_cache_init(kvm, &kvm->arch.xen.shinfo_cache, - gfn_to_gpa(gfn), PAGE_SIZE); - if (!ret) { - kvm->arch.xen.shinfo_set = true; + gpa, PAGE_SIZE); + if (ret) + goto out; + + kvm->arch.xen.shinfo_set = true; + + /* Paranoia checks on the 32-bit struct layout */ + BUILD_BUG_ON(offsetof(struct compat_shared_info, wc) != 0x900); + BUILD_BUG_ON(offsetof(struct compat_shared_info, arch.wc_sec_hi) != 0x924); + BUILD_BUG_ON(offsetof(struct pvclock_vcpu_time_info, version) != 0); + + /* 32-bit location by default */ + wc_ofs = offsetof(struct compat_shared_info, wc); + sec_hi_ofs = offsetof(struct compat_shared_info, arch.wc_sec_hi); + +#ifdef CONFIG_X86_64 + /* Paranoia checks on the 64-bit struct layout */ + BUILD_BUG_ON(offsetof(struct shared_info, wc) != 0xc00); + BUILD_BUG_ON(offsetof(struct shared_info, wc_sec_hi) != 0xc0c); + + if (kvm->arch.xen.long_mode) { + wc_ofs = offsetof(struct shared_info, wc); + sec_hi_ofs = offsetof(struct shared_info, wc_sec_hi); } +#endif + + kvm_write_wall_clock(kvm, gpa + wc_ofs, sec_hi_ofs - wc_ofs); + kvm_make_all_cpus_request(kvm, KVM_REQ_MASTERCLOCK_UPDATE); +out: srcu_read_unlock(&kvm->srcu, idx); return ret; } -- 2.7.4