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authorLinus Torvalds2022-03-06 12:08:42 -0800
committerLinus Torvalds2022-03-06 12:08:42 -0800
commitf81664f760046ac9b5731d9340f9e48e70ea7c8d (patch)
tree699215c6e870f125c14a79d3381f3f33f41792f4 /arch
parent9bdeaca18bf61d55029277bb35f72c2002c88c4d (diff)
parent8d25b7beca7ed6ca34f53f0f8abd009e2be15d94 (diff)
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini: "x86 guest: - Tweaks to the paravirtualization code, to avoid using them when they're pointless or harmful x86 host: - Fix for SRCU lockdep splat - Brown paper bag fix for the propagation of errno" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: pull kvm->srcu read-side to kvm_arch_vcpu_ioctl_run KVM: x86/mmu: Passing up the error state of mmu_alloc_shadow_roots() KVM: x86: Yield to IPI target vCPU only if it is busy x86/kvmclock: Fix Hyper-V Isolated VM's boot issue when vCPUs > 64 x86/kvm: Don't waste memory if kvmclock is disabled x86/kvm: Don't use PV TLB/yield when mwait is advertised
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/kvm.c4
-rw-r--r--arch/x86/kernel/kvmclock.c3
-rw-r--r--arch/x86/kvm/mmu/mmu.c2
-rw-r--r--arch/x86/kvm/x86.c25
4 files changed, 20 insertions, 14 deletions
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index f734e3b0cfec..d77481ecb0d5 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -463,6 +463,7 @@ static bool pv_tlb_flush_supported(void)
return (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH) &&
!kvm_para_has_hint(KVM_HINTS_REALTIME) &&
kvm_para_has_feature(KVM_FEATURE_STEAL_TIME) &&
+ !boot_cpu_has(X86_FEATURE_MWAIT) &&
(num_possible_cpus() != 1));
}
@@ -477,6 +478,7 @@ static bool pv_sched_yield_supported(void)
return (kvm_para_has_feature(KVM_FEATURE_PV_SCHED_YIELD) &&
!kvm_para_has_hint(KVM_HINTS_REALTIME) &&
kvm_para_has_feature(KVM_FEATURE_STEAL_TIME) &&
+ !boot_cpu_has(X86_FEATURE_MWAIT) &&
(num_possible_cpus() != 1));
}
@@ -622,7 +624,7 @@ static void kvm_smp_send_call_func_ipi(const struct cpumask *mask)
/* Make sure other vCPUs get a chance to run if they need to. */
for_each_cpu(cpu, mask) {
- if (vcpu_is_preempted(cpu)) {
+ if (!idle_cpu(cpu) && vcpu_is_preempted(cpu)) {
kvm_hypercall1(KVM_HC_SCHED_YIELD, per_cpu(x86_cpu_to_apicid, cpu));
break;
}
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index a35cbf9107af..c5caa7311bd8 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -239,6 +239,9 @@ static void __init kvmclock_init_mem(void)
static int __init kvm_setup_vsyscall_timeinfo(void)
{
+ if (!kvm_para_available() || !kvmclock)
+ return 0;
+
kvmclock_init_mem();
#ifdef CONFIG_X86_64
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 8e24f73bf60b..5628d0ba637e 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3565,7 +3565,7 @@ set_root_pgd:
out_unlock:
write_unlock(&vcpu->kvm->mmu_lock);
- return 0;
+ return r;
}
static int mmu_alloc_special_roots(struct kvm_vcpu *vcpu)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 82a9dcd8c67f..eb4029660bd9 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9180,6 +9180,7 @@ static int dm_request_for_irq_injection(struct kvm_vcpu *vcpu)
likely(!pic_in_kernel(vcpu->kvm));
}
+/* Called within kvm->srcu read side. */
static void post_kvm_run_save(struct kvm_vcpu *vcpu)
{
struct kvm_run *kvm_run = vcpu->run;
@@ -9188,16 +9189,9 @@ 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;
@@ -9815,6 +9809,7 @@ void __kvm_request_immediate_exit(struct kvm_vcpu *vcpu)
EXPORT_SYMBOL_GPL(__kvm_request_immediate_exit);
/*
+ * Called within kvm->srcu read side.
* Returns 1 to let vcpu_run() continue the guest execution loop without
* exiting to the userspace. Otherwise, the value will be returned to the
* userspace.
@@ -10193,6 +10188,7 @@ out:
return r;
}
+/* Called within kvm->srcu read side. */
static inline int vcpu_block(struct kvm *kvm, struct kvm_vcpu *vcpu)
{
bool hv_timer;
@@ -10252,12 +10248,12 @@ static inline bool kvm_vcpu_running(struct kvm_vcpu *vcpu)
!vcpu->arch.apf.halted);
}
+/* Called within kvm->srcu read side. */
static int vcpu_run(struct kvm_vcpu *vcpu)
{
int r;
struct kvm *kvm = vcpu->kvm;
- vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
vcpu->arch.l1tf_flush_l1d = true;
for (;;) {
@@ -10285,14 +10281,12 @@ static int vcpu_run(struct kvm_vcpu *vcpu)
if (__xfer_to_guest_mode_work_pending()) {
srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
r = xfer_to_guest_mode_handle_work(vcpu);
+ vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
if (r)
return r;
- vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
}
}
- srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
-
return r;
}
@@ -10398,6 +10392,7 @@ static void kvm_put_guest_fpu(struct kvm_vcpu *vcpu)
int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
{
struct kvm_run *kvm_run = vcpu->run;
+ struct kvm *kvm = vcpu->kvm;
int r;
vcpu_load(vcpu);
@@ -10405,6 +10400,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
kvm_run->flags = 0;
kvm_load_guest_fpu(vcpu);
+ vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
if (unlikely(vcpu->arch.mp_state == KVM_MP_STATE_UNINITIALIZED)) {
if (kvm_run->immediate_exit) {
r = -EINTR;
@@ -10415,7 +10411,11 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
* use before KVM has ever run the vCPU.
*/
WARN_ON_ONCE(kvm_lapic_hv_timer_in_use(vcpu));
+
+ srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
kvm_vcpu_block(vcpu);
+ vcpu->srcu_idx = srcu_read_lock(&kvm->srcu);
+
if (kvm_apic_accept_events(vcpu) < 0) {
r = 0;
goto out;
@@ -10475,8 +10475,9 @@ out:
if (kvm_run->kvm_valid_regs)
store_regs(vcpu);
post_kvm_run_save(vcpu);
- kvm_sigset_deactivate(vcpu);
+ srcu_read_unlock(&kvm->srcu, vcpu->srcu_idx);
+ kvm_sigset_deactivate(vcpu);
vcpu_put(vcpu);
return r;
}