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authorLinus Torvalds <torvalds@linux-foundation.org>2021-10-31 21:19:02 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-10-31 21:19:02 +0300
commitca5e83eddc8bc85db5698ef702b610ee64243459 (patch)
tree7296144779df9a1d8d3cb74136d38663e63b0584
parent180eca540ae06246d594bdd8d8213426a259cc8c (diff)
parentf3d1436d4bf8ced1c9a62a045d193a65567e1fcc (diff)
downloadlinux-ca5e83eddc8bc85db5698ef702b610ee64243459.tar.xz
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini: - Fixes for s390 interrupt delivery - Fixes for Xen emulator bugs showing up as debug kernel WARNs - Fix another issue with SEV/ES string I/O VMGEXITs * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: Take srcu lock in post_kvm_run_save() KVM: SEV-ES: fix another issue with string I/O VMGEXITs KVM: x86/xen: Fix kvm_xen_has_interrupt() sleeping in kvm_vcpu_block() KVM: x86: switch pvclock_gtod_sync_lock to a raw spinlock KVM: s390: preserve deliverable_mask in __airqs_kick_single_vcpu KVM: s390: clear kicked_mask before sleeping again
-rw-r--r--arch/s390/kvm/interrupt.c5
-rw-r--r--arch/s390/kvm/kvm-s390.c1
-rw-r--r--arch/x86/include/asm/kvm_host.h2
-rw-r--r--arch/x86/kvm/svm/sev.c15
-rw-r--r--arch/x86/kvm/x86.c36
-rw-r--r--arch/x86/kvm/xen.c27
6 files changed, 61 insertions, 25 deletions
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 10722455fd02..2245f4b8d362 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -3053,13 +3053,14 @@ static void __airqs_kick_single_vcpu(struct kvm *kvm, u8 deliverable_mask)
int vcpu_idx, online_vcpus = atomic_read(&kvm->online_vcpus);
struct kvm_s390_gisa_interrupt *gi = &kvm->arch.gisa_int;
struct kvm_vcpu *vcpu;
+ u8 vcpu_isc_mask;
for_each_set_bit(vcpu_idx, kvm->arch.idle_mask, online_vcpus) {
vcpu = kvm_get_vcpu(kvm, vcpu_idx);
if (psw_ioint_disabled(vcpu))
continue;
- deliverable_mask &= (u8)(vcpu->arch.sie_block->gcr[6] >> 24);
- if (deliverable_mask) {
+ vcpu_isc_mask = (u8)(vcpu->arch.sie_block->gcr[6] >> 24);
+ if (deliverable_mask & vcpu_isc_mask) {
/* lately kicked but not yet running */
if (test_and_set_bit(vcpu_idx, gi->kicked_mask))
return;
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 6a6dd5e1daf6..1c97493d21e1 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -3363,6 +3363,7 @@ out_free_sie_block:
int kvm_arch_vcpu_runnable(struct kvm_vcpu *vcpu)
{
+ clear_bit(vcpu->vcpu_idx, vcpu->kvm->arch.gisa_int.kicked_mask);
return kvm_s390_vcpu_has_irq(vcpu, 0);
}
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 5a0298aa56ba..13f64654dfff 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1098,7 +1098,7 @@ struct kvm_arch {
u64 cur_tsc_generation;
int nr_vcpus_matched_tsc;
- spinlock_t pvclock_gtod_sync_lock;
+ raw_spinlock_t pvclock_gtod_sync_lock;
bool use_master_clock;
u64 master_kernel_ns;
u64 master_cycle_now;
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 2e4916be290e..7e34d7163ada 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -2591,11 +2591,20 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
int sev_es_string_io(struct vcpu_svm *svm, int size, unsigned int port, int in)
{
- if (!setup_vmgexit_scratch(svm, in, svm->vmcb->control.exit_info_2))
+ int count;
+ int bytes;
+
+ if (svm->vmcb->control.exit_info_2 > INT_MAX)
+ return -EINVAL;
+
+ count = svm->vmcb->control.exit_info_2;
+ if (unlikely(check_mul_overflow(count, size, &bytes)))
+ return -EINVAL;
+
+ if (!setup_vmgexit_scratch(svm, in, bytes))
return -EINVAL;
- return kvm_sev_es_string_io(&svm->vcpu, size, port,
- svm->ghcb_sa, svm->ghcb_sa_len / size, in);
+ return kvm_sev_es_string_io(&svm->vcpu, size, port, svm->ghcb_sa, count, in);
}
void sev_es_init_vmcb(struct vcpu_svm *svm)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b26647a5ea22..bfe0de3008a6 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2542,7 +2542,7 @@ static void kvm_synchronize_tsc(struct kvm_vcpu *vcpu, u64 data)
kvm_vcpu_write_tsc_offset(vcpu, offset);
raw_spin_unlock_irqrestore(&kvm->arch.tsc_write_lock, flags);
- spin_lock_irqsave(&kvm->arch.pvclock_gtod_sync_lock, flags);
+ raw_spin_lock_irqsave(&kvm->arch.pvclock_gtod_sync_lock, flags);
if (!matched) {
kvm->arch.nr_vcpus_matched_tsc = 0;
} else if (!already_matched) {
@@ -2550,7 +2550,7 @@ static void kvm_synchronize_tsc(struct kvm_vcpu *vcpu, u64 data)
}
kvm_track_tsc_matching(vcpu);
- spin_unlock_irqrestore(&kvm->arch.pvclock_gtod_sync_lock, flags);
+ raw_spin_unlock_irqrestore(&kvm->arch.pvclock_gtod_sync_lock, flags);
}
static inline void adjust_tsc_offset_guest(struct kvm_vcpu *vcpu,
@@ -2780,9 +2780,9 @@ static void kvm_gen_update_masterclock(struct kvm *kvm)
kvm_make_mclock_inprogress_request(kvm);
/* no guest entries from this point */
- spin_lock_irqsave(&ka->pvclock_gtod_sync_lock, flags);
+ raw_spin_lock_irqsave(&ka->pvclock_gtod_sync_lock, flags);
pvclock_update_vm_gtod_copy(kvm);
- spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags);
+ raw_spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags);
kvm_for_each_vcpu(i, vcpu, kvm)
kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
@@ -2800,15 +2800,15 @@ u64 get_kvmclock_ns(struct kvm *kvm)
unsigned long flags;
u64 ret;
- spin_lock_irqsave(&ka->pvclock_gtod_sync_lock, flags);
+ raw_spin_lock_irqsave(&ka->pvclock_gtod_sync_lock, flags);
if (!ka->use_master_clock) {
- spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags);
+ raw_spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags);
return get_kvmclock_base_ns() + ka->kvmclock_offset;
}
hv_clock.tsc_timestamp = ka->master_cycle_now;
hv_clock.system_time = ka->master_kernel_ns + ka->kvmclock_offset;
- spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags);
+ raw_spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags);
/* both __this_cpu_read() and rdtsc() should be on the same cpu */
get_cpu();
@@ -2902,13 +2902,13 @@ static int kvm_guest_time_update(struct kvm_vcpu *v)
* If the host uses TSC clock, then passthrough TSC as stable
* to the guest.
*/
- spin_lock_irqsave(&ka->pvclock_gtod_sync_lock, flags);
+ raw_spin_lock_irqsave(&ka->pvclock_gtod_sync_lock, flags);
use_master_clock = ka->use_master_clock;
if (use_master_clock) {
host_tsc = ka->master_cycle_now;
kernel_ns = ka->master_kernel_ns;
}
- spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags);
+ raw_spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags);
/* Keep irq disabled to prevent changes to the clock */
local_irq_save(flags);
@@ -6100,13 +6100,13 @@ set_pit2_out:
* is slightly ahead) here we risk going negative on unsigned
* 'system_time' when 'user_ns.clock' is very small.
*/
- spin_lock_irq(&ka->pvclock_gtod_sync_lock);
+ raw_spin_lock_irq(&ka->pvclock_gtod_sync_lock);
if (kvm->arch.use_master_clock)
now_ns = ka->master_kernel_ns;
else
now_ns = get_kvmclock_base_ns();
ka->kvmclock_offset = user_ns.clock - now_ns;
- spin_unlock_irq(&ka->pvclock_gtod_sync_lock);
+ raw_spin_unlock_irq(&ka->pvclock_gtod_sync_lock);
kvm_make_all_cpus_request(kvm, KVM_REQ_CLOCK_UPDATE);
break;
@@ -8156,9 +8156,9 @@ static void kvm_hyperv_tsc_notifier(void)
list_for_each_entry(kvm, &vm_list, vm_list) {
struct kvm_arch *ka = &kvm->arch;
- spin_lock_irqsave(&ka->pvclock_gtod_sync_lock, flags);
+ raw_spin_lock_irqsave(&ka->pvclock_gtod_sync_lock, flags);
pvclock_update_vm_gtod_copy(kvm);
- spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags);
+ raw_spin_unlock_irqrestore(&ka->pvclock_gtod_sync_lock, flags);
kvm_for_each_vcpu(cpu, vcpu, kvm)
kvm_make_request(KVM_REQ_CLOCK_UPDATE, vcpu);
@@ -8800,9 +8800,17 @@ static void post_kvm_run_save(struct kvm_vcpu *vcpu)
kvm_run->cr8 = kvm_get_cr8(vcpu);
kvm_run->apic_base = kvm_get_apic_base(vcpu);
+
+ /*
+ * The call to kvm_ready_for_interrupt_injection() may end up in
+ * kvm_xen_has_interrupt() which may require the srcu lock to be
+ * held, to protect against changes in the vcpu_info address.
+ */
+ vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
kvm_run->ready_for_interrupt_injection =
pic_in_kernel(vcpu->kvm) ||
kvm_vcpu_ready_for_interrupt_injection(vcpu);
+ srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
if (is_smm(vcpu))
kvm_run->flags |= KVM_RUN_X86_SMM;
@@ -11199,7 +11207,7 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)
raw_spin_lock_init(&kvm->arch.tsc_write_lock);
mutex_init(&kvm->arch.apic_map_lock);
- spin_lock_init(&kvm->arch.pvclock_gtod_sync_lock);
+ raw_spin_lock_init(&kvm->arch.pvclock_gtod_sync_lock);
kvm->arch.kvmclock_offset = -get_kvmclock_base_ns();
pvclock_update_vm_gtod_copy(kvm);
diff --git a/arch/x86/kvm/xen.c b/arch/x86/kvm/xen.c
index 9ea9c3dabe37..8f62baebd028 100644
--- a/arch/x86/kvm/xen.c
+++ b/arch/x86/kvm/xen.c
@@ -190,6 +190,7 @@ void kvm_xen_update_runstate_guest(struct kvm_vcpu *v, int state)
int __kvm_xen_has_interrupt(struct kvm_vcpu *v)
{
+ int err;
u8 rc = 0;
/*
@@ -216,13 +217,29 @@ int __kvm_xen_has_interrupt(struct kvm_vcpu *v)
if (likely(slots->generation == ghc->generation &&
!kvm_is_error_hva(ghc->hva) && ghc->memslot)) {
/* Fast path */
- __get_user(rc, (u8 __user *)ghc->hva + offset);
- } else {
- /* Slow path */
- kvm_read_guest_offset_cached(v->kvm, ghc, &rc, offset,
- sizeof(rc));
+ pagefault_disable();
+ err = __get_user(rc, (u8 __user *)ghc->hva + offset);
+ pagefault_enable();
+ if (!err)
+ return rc;
}
+ /* Slow path */
+
+ /*
+ * This function gets called from kvm_vcpu_block() after setting the
+ * task to TASK_INTERRUPTIBLE, to see if it needs to wake immediately
+ * from a HLT. So we really mustn't sleep. If the page ended up absent
+ * at that point, just return 1 in order to trigger an immediate wake,
+ * and we'll end up getting called again from a context where we *can*
+ * fault in the page and wait for it.
+ */
+ if (in_atomic() || !task_is_running(current))
+ return 1;
+
+ kvm_read_guest_offset_cached(v->kvm, ghc, &rc, offset,
+ sizeof(rc));
+
return rc;
}