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authorPaolo Bonzini <pbonzini@redhat.com>2024-07-16 15:51:36 +0200
committerPaolo Bonzini <pbonzini@redhat.com>2024-07-16 15:51:36 +0200
commit86014c1e20fa1b5d5c6968f37fdd2f1b6c94d519 (patch)
treeef455cd218aa2009e04dd5a73e7d55dfa8ac009e
parentMerge tag 'kvm-x86-fixes-6.10-11' of https://github.com/kvm-x86/linux into HEAD (diff)
parentKVM: Add missing MODULE_DESCRIPTION() (diff)
downloadlinux-86014c1e20fa1b5d5c6968f37fdd2f1b6c94d519.tar.xz
linux-86014c1e20fa1b5d5c6968f37fdd2f1b6c94d519.zip
Merge tag 'kvm-x86-generic-6.11' of https://github.com/kvm-x86/linux into HEAD
KVM generic changes for 6.11 - Enable halt poll shrinking by default, as Intel found it to be a clear win. - Setup empty IRQ routing when creating a VM to avoid having to synchronize SRCU when creating a split IRQCHIP on x86. - Rework the sched_in/out() paths to replace kvm_arch_sched_in() with a flag that arch code can use for hooking both sched_in() and sched_out(). - Take the vCPU @id as an "unsigned long" instead of "u32" to avoid truncating a bogus value from userspace, e.g. to help userspace detect bugs. - Mark a vCPU as preempted if and only if it's scheduled out while in the KVM_RUN loop, e.g. to avoid marking it preempted and thus writing guest memory when retrieving guest state during live migration blackout. - A few minor cleanups
-rw-r--r--Documentation/virt/kvm/api.rst8
-rw-r--r--Documentation/virt/kvm/halt-polling.rst12
-rw-r--r--arch/arm64/include/asm/kvm_host.h1
-rw-r--r--arch/arm64/kvm/arm.c2
-rw-r--r--arch/loongarch/include/asm/kvm_host.h1
-rw-r--r--arch/loongarch/kvm/vcpu.c2
-rw-r--r--arch/mips/include/asm/kvm_host.h1
-rw-r--r--arch/mips/kvm/mips.c2
-rw-r--r--arch/powerpc/include/asm/kvm_host.h1
-rw-r--r--arch/powerpc/kvm/powerpc.c2
-rw-r--r--arch/riscv/include/asm/kvm_host.h1
-rw-r--r--arch/riscv/kvm/vcpu.c2
-rw-r--r--arch/s390/include/asm/kvm_host.h1
-rw-r--r--arch/s390/kvm/kvm-s390.c11
-rw-r--r--arch/x86/include/asm/kvm-x86-ops.h1
-rw-r--r--arch/x86/include/asm/kvm_host.h2
-rw-r--r--arch/x86/kvm/irq.h1
-rw-r--r--arch/x86/kvm/irq_comm.c7
-rw-r--r--arch/x86/kvm/pmu.c6
-rw-r--r--arch/x86/kvm/svm/svm.c11
-rw-r--r--arch/x86/kvm/vmx/main.c2
-rw-r--r--arch/x86/kvm/vmx/vmx.c80
-rw-r--r--arch/x86/kvm/vmx/x86_ops.h1
-rw-r--r--arch/x86/kvm/x86.c36
-rw-r--r--include/linux/kvm_host.h12
-rw-r--r--include/uapi/linux/kvm.h15
-rw-r--r--tools/testing/selftests/kvm/x86_64/max_vcpuid_cap_test.c22
-rw-r--r--tools/testing/selftests/kvm/x86_64/set_boot_cpu_id.c16
-rw-r--r--virt/kvm/async_pf.c13
-rw-r--r--virt/kvm/irqchip.c24
-rw-r--r--virt/kvm/kvm_main.c46
31 files changed, 196 insertions, 146 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 172cec187fc1..6ef7a08b745f 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -7969,10 +7969,10 @@ perform a bulk copy of tags to/from the guest.
7.29 KVM_CAP_VM_MOVE_ENC_CONTEXT_FROM
-------------------------------------
-Architectures: x86 SEV enabled
-Type: vm
-Parameters: args[0] is the fd of the source vm
-Returns: 0 on success
+:Architectures: x86 SEV enabled
+:Type: vm
+:Parameters: args[0] is the fd of the source vm
+:Returns: 0 on success
This capability enables userspace to migrate the encryption context from the VM
indicated by the fd to the VM this is called on.
diff --git a/Documentation/virt/kvm/halt-polling.rst b/Documentation/virt/kvm/halt-polling.rst
index c82a04b709b4..a6790a67e205 100644
--- a/Documentation/virt/kvm/halt-polling.rst
+++ b/Documentation/virt/kvm/halt-polling.rst
@@ -79,11 +79,11 @@ adjustment of the polling interval.
Module Parameters
=================
-The kvm module has 3 tuneable module parameters to adjust the global max
-polling interval as well as the rate at which the polling interval is grown and
-shrunk. These variables are defined in include/linux/kvm_host.h and as module
-parameters in virt/kvm/kvm_main.c, or arch/powerpc/kvm/book3s_hv.c in the
-powerpc kvm-hv case.
+The kvm module has 4 tunable module parameters to adjust the global max polling
+interval, the initial value (to grow from 0), and the rate at which the polling
+interval is grown and shrunk. These variables are defined in
+include/linux/kvm_host.h and as module parameters in virt/kvm/kvm_main.c, or
+arch/powerpc/kvm/book3s_hv.c in the powerpc kvm-hv case.
+-----------------------+---------------------------+-------------------------+
|Module Parameter | Description | Default Value |
@@ -105,7 +105,7 @@ powerpc kvm-hv case.
| | grow_halt_poll_ns() | |
| | function. | |
+-----------------------+---------------------------+-------------------------+
-|halt_poll_ns_shrink | The value by which the | 0 |
+|halt_poll_ns_shrink | The value by which the | 2 |
| | halt polling interval is | |
| | divided in the | |
| | shrink_halt_poll_ns() | |
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 25a3b72fbacf..a33f5996ca9f 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -1289,7 +1289,6 @@ static inline bool kvm_system_needs_idmapped_vectors(void)
}
static inline void kvm_arch_sync_events(struct kvm *kvm) {}
-static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
void kvm_arm_init_debug(void);
void kvm_arm_vcpu_init_debug(struct kvm_vcpu *vcpu);
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index c818818398a5..a7ca776b51ec 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1138,7 +1138,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
vcpu_load(vcpu);
- if (run->immediate_exit) {
+ if (!vcpu->wants_to_run) {
ret = -EINTR;
goto out;
}
diff --git a/arch/loongarch/include/asm/kvm_host.h b/arch/loongarch/include/asm/kvm_host.h
index fe38f98eeff8..44b54965f5b4 100644
--- a/arch/loongarch/include/asm/kvm_host.h
+++ b/arch/loongarch/include/asm/kvm_host.h
@@ -274,7 +274,6 @@ static inline bool kvm_is_ifetch_fault(struct kvm_vcpu_arch *arch)
static inline void kvm_arch_hardware_unsetup(void) {}
static inline void kvm_arch_sync_events(struct kvm *kvm) {}
static inline void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) {}
-static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {}
diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c
index bdfb1a910e27..16756ffb55e8 100644
--- a/arch/loongarch/kvm/vcpu.c
+++ b/arch/loongarch/kvm/vcpu.c
@@ -1416,7 +1416,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
kvm_complete_iocsr_read(vcpu, run);
}
- if (run->immediate_exit)
+ if (!vcpu->wants_to_run)
return r;
/* Clear exit_reason */
diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
index 179f320cc231..6743a57c1ab4 100644
--- a/arch/mips/include/asm/kvm_host.h
+++ b/arch/mips/include/asm/kvm_host.h
@@ -890,7 +890,6 @@ static inline void kvm_arch_sync_events(struct kvm *kvm) {}
static inline void kvm_arch_free_memslot(struct kvm *kvm,
struct kvm_memory_slot *slot) {}
static inline void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) {}
-static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 231ac052b506..f1a99962027a 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -436,7 +436,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
vcpu->mmio_needed = 0;
}
- if (vcpu->run->immediate_exit)
+ if (!vcpu->wants_to_run)
goto out;
lose_fpu(1);
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 8abac532146e..c4fb6a27fb92 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -897,7 +897,6 @@ struct kvm_vcpu_arch {
static inline void kvm_arch_sync_events(struct kvm *kvm) {}
static inline void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) {}
static inline void kvm_arch_flush_shadow_all(struct kvm *kvm) {}
-static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index d32abe7fe6ab..961aadc71de2 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -1852,7 +1852,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
kvm_sigset_activate(vcpu);
- if (run->immediate_exit)
+ if (!vcpu->wants_to_run)
r = -EINTR;
else
r = kvmppc_vcpu_run(vcpu);
diff --git a/arch/riscv/include/asm/kvm_host.h b/arch/riscv/include/asm/kvm_host.h
index d96281278586..dd77c2db6819 100644
--- a/arch/riscv/include/asm/kvm_host.h
+++ b/arch/riscv/include/asm/kvm_host.h
@@ -286,7 +286,6 @@ struct kvm_vcpu_arch {
};
static inline void kvm_arch_sync_events(struct kvm *kvm) {}
-static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
#define KVM_RISCV_GSTAGE_TLB_MIN_ORDER 12
diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index bc15df3119c3..1529161b0a5b 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -763,7 +763,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
return ret;
}
- if (run->immediate_exit) {
+ if (!vcpu->wants_to_run) {
kvm_vcpu_srcu_read_unlock(vcpu);
return -EINTR;
}
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index d8bbcac89ac3..978927f90529 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -1045,7 +1045,6 @@ extern int kvm_s390_gisc_register(struct kvm *kvm, u32 gisc);
extern int kvm_s390_gisc_unregister(struct kvm *kvm, u32 gisc);
static inline void kvm_arch_sync_events(struct kvm *kvm) {}
-static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
static inline void kvm_arch_free_memslot(struct kvm *kvm,
struct kvm_memory_slot *slot) {}
static inline void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen) {}
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 4a74effe6870..a68ed36adc9a 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -2997,14 +2997,9 @@ int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
break;
}
case KVM_CREATE_IRQCHIP: {
- struct kvm_irq_routing_entry routing;
-
r = -EINVAL;
- if (kvm->arch.use_irqchip) {
- /* Set up dummy routing. */
- memset(&routing, 0, sizeof(routing));
- r = kvm_set_irq_routing(kvm, &routing, 0, 0);
- }
+ if (kvm->arch.use_irqchip)
+ r = 0;
break;
}
case KVM_SET_DEVICE_ATTR: {
@@ -5032,7 +5027,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
if (vcpu->kvm->arch.pv.dumping)
return -EINVAL;
- if (kvm_run->immediate_exit)
+ if (!vcpu->wants_to_run)
return -EINTR;
if (kvm_run->kvm_valid_regs & ~KVM_SYNC_S390_VALID_FIELDS ||
diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index 566d19b02483..5a8b74c2e6c4 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -103,7 +103,6 @@ KVM_X86_OP(write_tsc_multiplier)
KVM_X86_OP(get_exit_info)
KVM_X86_OP(check_intercept)
KVM_X86_OP(handle_exit_irqoff)
-KVM_X86_OP(sched_in)
KVM_X86_OP_OPTIONAL(update_cpu_dirty_logging)
KVM_X86_OP_OPTIONAL(vcpu_blocking)
KVM_X86_OP_OPTIONAL(vcpu_unblocking)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 9bb2e164c523..058a5c67979d 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1750,8 +1750,6 @@ struct kvm_x86_ops {
struct x86_exception *exception);
void (*handle_exit_irqoff)(struct kvm_vcpu *vcpu);
- void (*sched_in)(struct kvm_vcpu *vcpu, int cpu);
-
/*
* Size of the CPU's dirty log buffer, i.e. VMX's PML buffer. A zero
* value indicates CPU dirty logging is unsupported or disabled.
diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h
index c2d7cfe82d00..76d46b2f41dd 100644
--- a/arch/x86/kvm/irq.h
+++ b/arch/x86/kvm/irq.h
@@ -106,7 +106,6 @@ void __kvm_migrate_timers(struct kvm_vcpu *vcpu);
int apic_has_pending_timer(struct kvm_vcpu *vcpu);
int kvm_setup_default_irq_routing(struct kvm *kvm);
-int kvm_setup_empty_irq_routing(struct kvm *kvm);
int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
struct kvm_lapic_irq *irq,
struct dest_map *dest_map);
diff --git a/arch/x86/kvm/irq_comm.c b/arch/x86/kvm/irq_comm.c
index 68f3f6c26046..8136695f7b96 100644
--- a/arch/x86/kvm/irq_comm.c
+++ b/arch/x86/kvm/irq_comm.c
@@ -395,13 +395,6 @@ int kvm_setup_default_irq_routing(struct kvm *kvm)
ARRAY_SIZE(default_routing), 0);
}
-static const struct kvm_irq_routing_entry empty_routing[] = {};
-
-int kvm_setup_empty_irq_routing(struct kvm *kvm)
-{
- return kvm_set_irq_routing(kvm, empty_routing, 0, 0);
-}
-
void kvm_arch_post_irq_routing_update(struct kvm *kvm)
{
if (!irqchip_split(kvm))
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index a593b03c9aed..f9149c9fc275 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -521,9 +521,9 @@ void kvm_pmu_handle_event(struct kvm_vcpu *vcpu)
}
/*
- * Unused perf_events are only released if the corresponding MSRs
- * weren't accessed during the last vCPU time slice. kvm_arch_sched_in
- * triggers KVM_REQ_PMU if cleanup is needed.
+ * Release unused perf_events if the corresponding guest MSRs weren't
+ * accessed during the last vCPU time slice (need_cleanup is set when
+ * the vCPU is scheduled back in).
*/
if (unlikely(pmu->need_cleanup))
kvm_pmu_cleanup(vcpu);
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index c58da281f14f..80ac33a5effe 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -1554,6 +1554,9 @@ static void svm_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
struct vcpu_svm *svm = to_svm(vcpu);
struct svm_cpu_data *sd = per_cpu_ptr(&svm_data, cpu);
+ if (vcpu->scheduled_out && !kvm_pause_in_guest(vcpu->kvm))
+ shrink_ple_window(vcpu);
+
if (sd->current_vmcb != svm->vmcb) {
sd->current_vmcb = svm->vmcb;
@@ -4607,12 +4610,6 @@ static void svm_handle_exit_irqoff(struct kvm_vcpu *vcpu)
vcpu->arch.at_instruction_boundary = true;
}
-static void svm_sched_in(struct kvm_vcpu *vcpu, int cpu)
-{
- if (!kvm_pause_in_guest(vcpu->kvm))
- shrink_ple_window(vcpu);
-}
-
static void svm_setup_mce(struct kvm_vcpu *vcpu)
{
/* [63:9] are reserved. */
@@ -5075,8 +5072,6 @@ static struct kvm_x86_ops svm_x86_ops __initdata = {
.check_intercept = svm_check_intercept,
.handle_exit_irqoff = svm_handle_exit_irqoff,
- .sched_in = svm_sched_in,
-
.nested_ops = &svm_nested_ops,
.deliver_interrupt = svm_deliver_interrupt,
diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c
index d4ed681785fd..c7a86be0f30e 100644
--- a/arch/x86/kvm/vmx/main.c
+++ b/arch/x86/kvm/vmx/main.c
@@ -122,8 +122,6 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
.check_intercept = vmx_check_intercept,
.handle_exit_irqoff = vmx_handle_exit_irqoff,
- .sched_in = vmx_sched_in,
-
.cpu_dirty_log_size = PML_ENTITY_NUM,
.update_cpu_dirty_logging = vmx_update_cpu_dirty_logging,
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index b3c83c06f826..078386582782 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -1411,6 +1411,38 @@ static void vmx_write_guest_kernel_gs_base(struct vcpu_vmx *vmx, u64 data)
}
#endif
+static void grow_ple_window(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
+ unsigned int old = vmx->ple_window;
+
+ vmx->ple_window = __grow_ple_window(old, ple_window,
+ ple_window_grow,
+ ple_window_max);
+
+ if (vmx->ple_window != old) {
+ vmx->ple_window_dirty = true;
+ trace_kvm_ple_window_update(vcpu->vcpu_id,
+ vmx->ple_window, old);
+ }
+}
+
+static void shrink_ple_window(struct kvm_vcpu *vcpu)
+{
+ struct vcpu_vmx *vmx = to_vmx(vcpu);
+ unsigned int old = vmx->ple_window;
+
+ vmx->ple_window = __shrink_ple_window(old, ple_window,
+ ple_window_shrink,
+ ple_window);
+
+ if (vmx->ple_window != old) {
+ vmx->ple_window_dirty = true;
+ trace_kvm_ple_window_update(vcpu->vcpu_id,
+ vmx->ple_window, old);
+ }
+}
+
void vmx_vcpu_load_vmcs(struct kvm_vcpu *vcpu, int cpu,
struct loaded_vmcs *buddy)
{
@@ -1486,6 +1518,9 @@ void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
+ if (vcpu->scheduled_out && !kvm_pause_in_guest(vcpu->kvm))
+ shrink_ple_window(vcpu);
+
vmx_vcpu_load_vmcs(vcpu, cpu, NULL);
vmx_vcpu_pi_load(vcpu, cpu);
@@ -5897,38 +5932,6 @@ int vmx_vcpu_pre_run(struct kvm_vcpu *vcpu)
return 1;
}
-static void grow_ple_window(struct kvm_vcpu *vcpu)
-{
- struct vcpu_vmx *vmx = to_vmx(vcpu);
- unsigned int old = vmx->ple_window;
-
- vmx->ple_window = __grow_ple_window(old, ple_window,
- ple_window_grow,
- ple_window_max);
-
- if (vmx->ple_window != old) {
- vmx->ple_window_dirty = true;
- trace_kvm_ple_window_update(vcpu->vcpu_id,
- vmx->ple_window, old);
- }
-}
-
-static void shrink_ple_window(struct kvm_vcpu *vcpu)
-{
- struct vcpu_vmx *vmx = to_vmx(vcpu);
- unsigned int old = vmx->ple_window;
-
- vmx->ple_window = __shrink_ple_window(old, ple_window,
- ple_window_shrink,
- ple_window);
-
- if (vmx->ple_window != old) {
- vmx->ple_window_dirty = true;
- trace_kvm_ple_window_update(vcpu->vcpu_id,
- vmx->ple_window, old);
- }
-}
-
/*
* Indicate a busy-waiting vcpu in spinlock. We do not enable the PAUSE
* exiting, so only get here on cpu with PAUSE-Loop-Exiting.
@@ -6677,9 +6680,10 @@ static noinstr void vmx_l1d_flush(struct kvm_vcpu *vcpu)
bool flush_l1d;
/*
- * Clear the per-vcpu flush bit, it gets set again
- * either from vcpu_run() or from one of the unsafe
- * VMEXIT handlers.
+ * Clear the per-vcpu flush bit, it gets set again if the vCPU
+ * is reloaded, i.e. if the vCPU is scheduled out or if KVM
+ * exits to userspace, or if KVM reaches one of the unsafe
+ * VMEXIT handlers, e.g. if KVM calls into the emulator.
*/
flush_l1d = vcpu->arch.l1tf_flush_l1d;
vcpu->arch.l1tf_flush_l1d = false;
@@ -8179,12 +8183,6 @@ void vmx_cancel_hv_timer(struct kvm_vcpu *vcpu)
}
#endif
-void vmx_sched_in(struct kvm_vcpu *vcpu, int cpu)
-{
- if (!kvm_pause_in_guest(vcpu->kvm))
- shrink_ple_window(vcpu);
-}
-
void vmx_update_cpu_dirty_logging(struct kvm_vcpu *vcpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h
index 502704596c83..3cb0be94e779 100644
--- a/arch/x86/kvm/vmx/x86_ops.h
+++ b/arch/x86/kvm/vmx/x86_ops.h
@@ -112,7 +112,6 @@ u64 vmx_get_l2_tsc_multiplier(struct kvm_vcpu *vcpu);
void vmx_write_tsc_offset(struct kvm_vcpu *vcpu);
void vmx_write_tsc_multiplier(struct kvm_vcpu *vcpu);
void vmx_request_immediate_exit(struct kvm_vcpu *vcpu);
-void vmx_sched_in(struct kvm_vcpu *vcpu, int cpu);
void vmx_update_cpu_dirty_logging(struct kvm_vcpu *vcpu);
#ifdef CONFIG_X86_64
int vmx_set_hv_timer(struct kvm_vcpu *vcpu, u64 guest_deadline_tsc,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index a6968eadd418..e8c34f8e1964 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4998,6 +4998,15 @@ static bool need_emulate_wbinvd(struct kvm_vcpu *vcpu)
void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
+ struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
+
+ vcpu->arch.l1tf_flush_l1d = true;
+
+ if (vcpu->scheduled_out && pmu->version && pmu->event_count) {
+ pmu->need_cleanup = true;
+ kvm_make_request(KVM_REQ_PMU, vcpu);
+ }
+
/* Address WBINVD may be executed by guest */
if (need_emulate_wbinvd(vcpu)) {
if (static_call(kvm_x86_has_wbinvd_exit)())
@@ -6546,9 +6555,6 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
goto split_irqchip_unlock;
if (kvm->created_vcpus)
goto split_irqchip_unlock;
- r = kvm_setup_empty_irq_routing(kvm);
- if (r)
- goto split_irqchip_unlock;
/* Pairs with irqchip_in_kernel. */
smp_wmb();
kvm->arch.irqchip_mode = KVM_IRQCHIP_SPLIT;
@@ -6695,7 +6701,9 @@ split_irqchip_unlock:
break;
mutex_lock(&kvm->lock);
- if (kvm->arch.max_vcpu_ids == cap->args[0]) {
+ if (kvm->arch.bsp_vcpu_id > cap->args[0]) {
+ ;
+ } else if (kvm->arch.max_vcpu_ids == cap->args[0]) {
r = 0;
} else if (!kvm->arch.max_vcpu_ids) {
kvm->arch.max_vcpu_ids = cap->args[0];
@@ -7216,6 +7224,9 @@ set_pit2_out:
mutex_lock(&kvm->lock);
if (kvm->created_vcpus)
r = -EBUSY;
+ else if (arg > KVM_MAX_VCPU_IDS ||
+ (kvm->arch.max_vcpu_ids && arg > kvm->arch.max_vcpu_ids))
+ r = -EINVAL;
else
kvm->arch.bsp_vcpu_id = arg;
mutex_unlock(&kvm->lock);
@@ -11248,7 +11259,6 @@ static int vcpu_run(struct kvm_vcpu *vcpu)
int r;
vcpu->run->exit_reason = KVM_EXIT_UNKNOWN;
- vcpu->arch.l1tf_flush_l1d = true;
for (;;) {
/*
@@ -11398,7 +11408,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
kvm_vcpu_srcu_read_lock(vcpu);
if (unlikely(vcpu->arch.mp_state == KVM_MP_STATE_UNINITIALIZED)) {
- if (kvm_run->immediate_exit) {
+ if (!vcpu->wants_to_run) {
r = -EINTR;
goto out;
}
@@ -11476,7 +11486,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu)
WARN_ON_ONCE(vcpu->mmio_needed);
}
- if (kvm_run->immediate_exit) {
+ if (!vcpu->wants_to_run) {
r = -EINTR;
goto out;
}
@@ -12569,18 +12579,6 @@ bool kvm_vcpu_is_bsp(struct kvm_vcpu *vcpu)
return (vcpu->arch.apic_base & MSR_IA32_APICBASE_BSP) != 0;
}
-void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)
-{
- struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
-
- vcpu->arch.l1tf_flush_l1d = true;
- if (pmu->version && unlikely(pmu->event_count)) {
- pmu->need_cleanup = true;
- kvm_make_request(KVM_REQ_PMU, vcpu);
- }
- static_call(kvm_x86_sched_in)(vcpu, cpu);
-}
-
void kvm_arch_free_vm(struct kvm *kvm)
{
#if IS_ENABLED(CONFIG_HYPERV)
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index c3c922bf077f..689e8be873a7 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -378,8 +378,10 @@ struct kvm_vcpu {
bool dy_eligible;
} spin_loop;
#endif
+ bool wants_to_run;
bool preempted;
bool ready;
+ bool scheduled_out;
struct kvm_vcpu_arch arch;
struct kvm_vcpu_stat stat;
char stats_id[KVM_STATS_NAME_SIZE];
@@ -1494,8 +1496,6 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
struct kvm_guest_debug *dbg);
int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu);
-void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu);
-
void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu);
void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu);
int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id);
@@ -1955,8 +1955,6 @@ struct _kvm_stats_desc {
HALT_POLL_HIST_COUNT), \
STATS_DESC_IBOOLEAN(VCPU_GENERIC, blocking)
-extern struct dentry *kvm_debugfs_dir;
-
ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
const struct _kvm_stats_desc *desc,
void *stats, size_t size_stats,
@@ -2096,6 +2094,7 @@ int kvm_set_irq_routing(struct kvm *kvm,
const struct kvm_irq_routing_entry *entries,
unsigned nr,
unsigned flags);
+int kvm_init_irq_routing(struct kvm *kvm);
int kvm_set_routing_entry(struct kvm *kvm,
struct kvm_kernel_irq_routing_entry *e,
const struct kvm_irq_routing_entry *ue);
@@ -2105,6 +2104,11 @@ void kvm_free_irq_routing(struct kvm *kvm);
static inline void kvm_free_irq_routing(struct kvm *kvm) {}
+static inline int kvm_init_irq_routing(struct kvm *kvm)
+{
+ return 0;
+}
+
#endif
int kvm_send_userspace_msi(struct kvm *kvm, struct kvm_msi *msi);
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index e5af8c692dc0..1053e7c5eab9 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -192,11 +192,24 @@ struct kvm_xen_exit {
/* Flags that describe what fields in emulation_failure hold valid data. */
#define KVM_INTERNAL_ERROR_EMULATION_FLAG_INSTRUCTION_BYTES (1ULL << 0)
+/*
+ * struct kvm_run can be modified by userspace at any time, so KVM must be
+ * careful to avoid TOCTOU bugs. In order to protect KVM, HINT_UNSAFE_IN_KVM()
+ * renames fields in struct kvm_run from <symbol> to <symbol>__unsafe when
+ * compiled into the kernel, ensuring that any use within KVM is obvious and
+ * gets extra scrutiny.
+ */
+#ifdef __KERNEL__
+#define HINT_UNSAFE_IN_KVM(_symbol) _symbol##__unsafe
+#else
+#define HINT_UNSAFE_IN_KVM(_symbol) _symbol
+#endif
+
/* for KVM_RUN, returned by mmap(vcpu_fd, offset=0) */
struct kvm_run {
/* in */
__u8 request_interrupt_window;
- __u8 immediate_exit;
+ __u8 HINT_UNSAFE_IN_KVM(immediate_exit);
__u8 padding1[6];
/* out */
diff --git a/tools/testing/selftests/kvm/x86_64/max_vcpuid_cap_test.c b/tools/testing/selftests/kvm/x86_64/max_vcpuid_cap_test.c
index 3cc4b86832fe..7e2bfb3c3f3b 100644
--- a/tools/testing/selftests/kvm/x86_64/max_vcpuid_cap_test.c
+++ b/tools/testing/selftests/kvm/x86_64/max_vcpuid_cap_test.c
@@ -26,19 +26,37 @@ int main(int argc, char *argv[])
TEST_ASSERT(ret < 0,
"Setting KVM_CAP_MAX_VCPU_ID beyond KVM cap should fail");
+ /* Test BOOT_CPU_ID interaction (MAX_VCPU_ID cannot be lower) */
+ if (kvm_has_cap(KVM_CAP_SET_BOOT_CPU_ID)) {
+ vm_ioctl(vm, KVM_SET_BOOT_CPU_ID, (void *)MAX_VCPU_ID);
+
+ /* Try setting KVM_CAP_MAX_VCPU_ID below BOOT_CPU_ID */
+ ret = __vm_enable_cap(vm, KVM_CAP_MAX_VCPU_ID, MAX_VCPU_ID - 1);
+ TEST_ASSERT(ret < 0,
+ "Setting KVM_CAP_MAX_VCPU_ID below BOOT_CPU_ID should fail");
+ }
+
/* Set KVM_CAP_MAX_VCPU_ID */
vm_enable_cap(vm, KVM_CAP_MAX_VCPU_ID, MAX_VCPU_ID);
-
/* Try to set KVM_CAP_MAX_VCPU_ID again */
ret = __vm_enable_cap(vm, KVM_CAP_MAX_VCPU_ID, MAX_VCPU_ID + 1);
TEST_ASSERT(ret < 0,
"Setting KVM_CAP_MAX_VCPU_ID multiple times should fail");
- /* Create vCPU with id beyond KVM_CAP_MAX_VCPU_ID cap*/
+ /* Create vCPU with id beyond KVM_CAP_MAX_VCPU_ID cap */
ret = __vm_ioctl(vm, KVM_CREATE_VCPU, (void *)MAX_VCPU_ID);
TEST_ASSERT(ret < 0, "Creating vCPU with ID > MAX_VCPU_ID should fail");
+ /* Create vCPU with bits 63:32 != 0, but an otherwise valid id */
+ ret = __vm_ioctl(vm, KVM_CREATE_VCPU, (void *)(1L << 32));
+ TEST_ASSERT(ret < 0, "Creating vCPU with ID[63:32] != 0 should fail");
+
+ /* Create vCPU with id within bounds */
+ ret = __vm_ioctl(vm, KVM_CREATE_VCPU, (void *)0);
+ TEST_ASSERT(ret >= 0, "Creating vCPU with ID 0 should succeed");
+
+ close(ret);
kvm_vm_free(vm);
return 0;
}
diff --git a/tools/testing/selftests/kvm/x86_64/set_boot_cpu_id.c b/tools/testing/selftests/kvm/x86_64/set_boot_cpu_id.c
index d691d86e5bc3..49913784bc82 100644
--- a/tools/testing/selftests/kvm/x86_64/set_boot_cpu_id.c
+++ b/tools/testing/selftests/kvm/x86_64/set_boot_cpu_id.c
@@ -33,6 +33,20 @@ static void guest_not_bsp_vcpu(void *arg)
GUEST_DONE();
}
+static void test_set_invalid_bsp(struct kvm_vm *vm)
+{
+ unsigned long max_vcpu_id = vm_check_cap(vm, KVM_CAP_MAX_VCPU_ID);
+ int r;
+
+ if (max_vcpu_id) {
+ r = __vm_ioctl(vm, KVM_SET_BOOT_CPU_ID, (void *)(max_vcpu_id + 1));
+ TEST_ASSERT(r == -1 && errno == EINVAL, "BSP with ID > MAX should fail");
+ }
+
+ r = __vm_ioctl(vm, KVM_SET_BOOT_CPU_ID, (void *)(1L << 32));
+ TEST_ASSERT(r == -1 && errno == EINVAL, "BSP with ID[63:32]!=0 should fail");
+}
+
static void test_set_bsp_busy(struct kvm_vcpu *vcpu, const char *msg)
{
int r = __vm_ioctl(vcpu->vm, KVM_SET_BOOT_CPU_ID,
@@ -80,6 +94,8 @@ static struct kvm_vm *create_vm(uint32_t nr_vcpus, uint32_t bsp_vcpu_id,
vm = vm_create(nr_vcpus);
+ test_set_invalid_bsp(vm);
+
vm_ioctl(vm, KVM_SET_BOOT_CPU_ID, (void *)(unsigned long)bsp_vcpu_id);
for (i = 0; i < nr_vcpus; i++)
diff --git a/virt/kvm/async_pf.c b/virt/kvm/async_pf.c
index 99a63bad0306..0ee4816b079a 100644
--- a/virt/kvm/async_pf.c
+++ b/virt/kvm/async_pf.c
@@ -80,7 +80,6 @@ static void async_pf_execute(struct work_struct *work)
spin_lock(&vcpu->async_pf.lock);
first = list_empty(&vcpu->async_pf.done);
list_add_tail(&apf->link, &vcpu->async_pf.done);
- apf->vcpu = NULL;
spin_unlock(&vcpu->async_pf.lock);
/*
@@ -120,8 +119,6 @@ static void kvm_flush_and_free_async_pf_work(struct kvm_async_pf *work)
void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu)
{
- spin_lock(&vcpu->async_pf.lock);
-
/* cancel outstanding work queue item */
while (!list_empty(&vcpu->async_pf.queue)) {
struct kvm_async_pf *work =
@@ -129,23 +126,15 @@ void kvm_clear_async_pf_completion_queue(struct kvm_vcpu *vcpu)
typeof(*work), queue);
list_del(&work->queue);
- /*
- * We know it's present in vcpu->async_pf.done, do
- * nothing here.
- */
- if (!work->vcpu)
- continue;
-
- spin_unlock(&vcpu->async_pf.lock);
#ifdef CONFIG_KVM_ASYNC_PF_SYNC
flush_work(&work->work);
#else
if (cancel_work_sync(&work->work))
kmem_cache_free(async_pf_cache, work);
#endif
- spin_lock(&vcpu->async_pf.lock);
}
+ spin_lock(&vcpu->async_pf.lock);
while (!list_empty(&vcpu->async_pf.done)) {
struct kvm_async_pf *work =
list_first_entry(&vcpu->async_pf.done,
diff --git a/virt/kvm/irqchip.c b/virt/kvm/irqchip.c
index 1e567d1f6d3d..162d8ed889f2 100644
--- a/virt/kvm/irqchip.c
+++ b/virt/kvm/irqchip.c
@@ -237,3 +237,27 @@ out:
return r;
}
+
+/*
+ * Allocate empty IRQ routing by default so that additional setup isn't needed
+ * when userspace-driven IRQ routing is activated, and so that kvm->irq_routing
+ * is guaranteed to be non-NULL.
+ */
+int kvm_init_irq_routing(struct kvm *kvm)
+{
+ struct kvm_irq_routing_table *new;
+ int chip_size;
+
+ new = kzalloc(struct_size(new, map, 1), GFP_KERNEL_ACCOUNT);
+ if (!new)
+ return -ENOMEM;
+
+ new->nr_rt_entries = 1;
+
+ chip_size = sizeof(int) * KVM_NR_IRQCHIPS * KVM_IRQCHIP_NUM_PINS;
+ memset(new->chip, -1, chip_size);
+
+ RCU_INIT_POINTER(kvm->irq_routing, new);
+
+ return 0;
+}
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 3282ff98b3a3..d0788d0a72cc 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1,9 +1,6 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
- * Kernel-based Virtual Machine driver for Linux
- *
- * This module enables machines with Intel VT-x extensions to run virtual
- * machines without emulation or binary translation.
+ * Kernel-based Virtual Machine (KVM) Hypervisor
*
* Copyright (C) 2006 Qumranet, Inc.
* Copyright 2010 Red Hat, Inc. and/or its affiliates.
@@ -74,6 +71,7 @@
#define ITOA_MAX_LEN 12
MODULE_AUTHOR("Qumranet");
+MODULE_DESCRIPTION("Kernel-based Virtual Machine (KVM) Hypervisor");
MODULE_LICENSE("GPL");
/* Architectures should define their poll value according to the halt latency */
@@ -91,8 +89,8 @@ unsigned int halt_poll_ns_grow_start = 10000; /* 10us */
module_param(halt_poll_ns_grow_start, uint, 0644);
EXPORT_SYMBOL_GPL(halt_poll_ns_grow_start);
-/* Default resets per-vcpu halt_poll_ns . */
-unsigned int halt_poll_ns_shrink;
+/* Default halves per-vcpu halt_poll_ns. */
+unsigned int halt_poll_ns_shrink = 2;
module_param(halt_poll_ns_shrink, uint, 0644);
EXPORT_SYMBOL_GPL(halt_poll_ns_shrink);
@@ -110,8 +108,7 @@ static struct kmem_cache *kvm_vcpu_cache;
static __read_mostly struct preempt_ops kvm_preempt_ops;
static DEFINE_PER_CPU(struct kvm_vcpu *, kvm_running_vcpu);
-struct dentry *kvm_debugfs_dir;
-EXPORT_SYMBOL_GPL(kvm_debugfs_dir);
+static struct dentry *kvm_debugfs_dir;
static const struct file_operations stat_fops_per_vm;
@@ -1145,8 +1142,7 @@ static struct kvm *kvm_create_vm(unsigned long type, const char *fdname)
{
struct kvm *kvm = kvm_arch_alloc_vm();
struct kvm_memslots *slots;
- int r = -ENOMEM;
- int i, j;
+ int r, i, j;
if (!kvm)
return ERR_PTR(-ENOMEM);
@@ -1183,12 +1179,18 @@ static struct kvm *kvm_create_vm(unsigned long type, const char *fdname)
snprintf(kvm->stats_id, sizeof(kvm->stats_id), "kvm-%d",
task_pid_nr(current));
+ r = -ENOMEM;
if (init_srcu_struct(&kvm->srcu))
goto out_err_no_srcu;
if (init_srcu_struct(&kvm->irq_srcu))
goto out_err_no_irq_srcu;
+ r = kvm_init_irq_routing(kvm);
+ if (r)
+ goto out_err_no_irq_routing;
+
refcount_set(&kvm->users_count, 1);
+
for (i = 0; i < kvm_arch_nr_memslot_as_ids(kvm); i++) {
for (j = 0; j < 2; j++) {
slots = &kvm->__memslots[i][j];
@@ -1206,6 +1208,7 @@ static struct kvm *kvm_create_vm(unsigned long type, const char *fdname)
rcu_assign_pointer(kvm->memslots[i], &kvm->__memslots[i][0]);
}
+ r = -ENOMEM;
for (i = 0; i < KVM_NR_BUSES; i++) {
rcu_assign_pointer(kvm->buses[i],
kzalloc(sizeof(struct kvm_io_bus), GFP_KERNEL_ACCOUNT));
@@ -1267,6 +1270,8 @@ out_err_no_arch_destroy_vm:
WARN_ON_ONCE(!refcount_dec_and_test(&kvm->users_count));
for (i = 0; i < KVM_NR_BUSES; i++)
kfree(kvm_get_bus(kvm, i));
+ kvm_free_irq_routing(kvm);
+out_err_no_irq_routing:
cleanup_srcu_struct(&kvm->irq_srcu);
out_err_no_irq_srcu:
cleanup_srcu_struct(&kvm->srcu);
@@ -4202,12 +4207,21 @@ static void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu)
/*
* Creates some virtual cpus. Good luck creating more than one.
*/
-static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id)
+static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, unsigned long id)
{
int r;
struct kvm_vcpu *vcpu;
struct page *page;
+ /*
+ * KVM tracks vCPU IDs as 'int', be kind to userspace and reject
+ * too-large values instead of silently truncating.
+ *
+ * Ensure KVM_MAX_VCPU_IDS isn't pushed above INT_MAX without first
+ * changing the storage type (at the very least, IDs should be tracked
+ * as unsigned ints).
+ */
+ BUILD_BUG_ON(KVM_MAX_VCPU_IDS > INT_MAX);
if (id >= KVM_MAX_VCPU_IDS)
return -EINVAL;
@@ -4467,7 +4481,10 @@ static long kvm_vcpu_ioctl(struct file *filp,
synchronize_rcu();
put_pid(oldpid);
}
+ vcpu->wants_to_run = !READ_ONCE(vcpu->run->immediate_exit__unsafe);
r = kvm_arch_vcpu_ioctl_run(vcpu);
+ vcpu->wants_to_run = false;
+
trace_kvm_userspace_exit(vcpu->run->exit_reason, r);
break;
}
@@ -6347,8 +6364,9 @@ static void kvm_sched_in(struct preempt_notifier *pn, int cpu)
WRITE_ONCE(vcpu->ready, false);
__this_cpu_write(kvm_running_vcpu, vcpu);
- kvm_arch_sched_in(vcpu, cpu);
kvm_arch_vcpu_load(vcpu, cpu);
+
+ WRITE_ONCE(vcpu->scheduled_out, false);
}
static void kvm_sched_out(struct preempt_notifier *pn,
@@ -6356,7 +6374,9 @@ static void kvm_sched_out(struct preempt_notifier *pn,
{
struct kvm_vcpu *vcpu = preempt_notifier_to_vcpu(pn);
- if (current->on_rq) {
+ WRITE_ONCE(vcpu->scheduled_out, true);
+
+ if (current->on_rq && vcpu->wants_to_run) {
WRITE_ONCE(vcpu->preempted, true);
WRITE_ONCE(vcpu->ready, true);
}