KVM: x86: Handle SRCU initialization failure during page track init
Subsystems (2)
Sasha Levin
maintainerPATCH 1/4 KVM: x86: Handle SRCU initialization failure during page track init
From: Haimin Zhang <[email protected]>
[ Upstream commit eb7511bf9182292ef1df1082d23039e856d1ddfb ]
Check the return of init_srcu_struct(), which can fail due to OOM, when initializing the page track mechanism. Lack of checking leads to a NULL pointer deref found by a modified syzkaller.
Message-Id: <[email protected]>
--- arch/x86/include/asm/kvm_page_track.h | 2 +- arch/x86/kvm/page_track.c | 4 ++-- arch/x86/kvm/x86.c | 7 ++++++- 3 files changed, 9 insertions(+), 4 deletions(-)
arch/x86/include/asm/kvm_page_track.h +1 -1
@@ -46,7 +46,7 @@ struct kvm_page_track_notifier_node { struct kvm_page_track_notifier_node *node); }; -void kvm_page_track_init (struct kvm *kvm); +int kvm_page_track_init (struct kvm *kvm);void kvm_page_track_cleanup (struct kvm *kvm); void kvm_page_track_free_memslot(struct kvm_memory_slot *free,
arch/x86/kvm/page_track.c +2 -2
@@ -167,13 +167,13 @@ void kvm_page_track_cleanup(struct kvm *kvm)cleanup_srcu_struct (&head->track_srcu); } -void kvm_page_track_init (struct kvm *kvm) +int kvm_page_track_init (struct kvm *kvm) {struct kvm_page_track_notifier_head *head; head = &kvm->arch.track_notifier_head; -init_srcu_struct (&head->track_srcu);INIT_HLIST_HEAD (&head->track_notifier_list); +return init_srcu_struct (&head->track_srcu); }/*
arch/x86/kvm/x86.c +6 -1
@@ -9585,9 +9585,15 @@ void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)int kvm_arch_init_vm (struct kvm *kvm,unsigned long type) { +int ret; +if (type)return -EINVAL ; + ret =kvm_page_track_init (kvm); +if (ret) +return ret; +INIT_HLIST_HEAD (&kvm->arch.mask_notifier_list);INIT_LIST_HEAD (&kvm->arch.active_mmu_pages);INIT_LIST_HEAD (&kvm->arch.zapped_obsolete_pages);
@@ -9614,7 +9620,6 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)INIT_DELAYED_WORK (&kvm->arch.kvmclock_sync_work, kvmclock_sync_fn);kvm_hv_init_vm (kvm); -kvm_page_track_init (kvm);kvm_mmu_init_vm (kvm);return kvm_x86_ops->vm_init (kvm);
Signature · 1 line
2.33.0
Sasha Levin
maintainerPATCH 2/4 KVM: do not shrink halt_poll_ns below grow_start
From: Sergey Senozhatsky <[email protected]>
[ Upstream commit ae232ea460888dc5a8b37e840c553b02521fbf18 ]
grow_halt_poll_ns() ignores values between 0 and halt_poll_ns_grow_start (10000 by default). However, when we shrink halt_poll_ns we may fall way below halt_poll_ns_grow_start and endup with halt_poll_ns values that don't make a lot of sense: like 1 or 9, or 19.
VCPU1 trace (halt_poll_ns_shrink equals 2):
VCPU1 grow 10000
VCPU1 shrink 5000
VCPU1 shrink 2500
VCPU1 shrink 1250
VCPU1 shrink 625
VCPU1 shrink 312
VCPU1 shrink 156
VCPU1 shrink 78
VCPU1 shrink 39
VCPU1 shrink 19
VCPU1 shrink 9
VCPU1 shrink 4
Mirror what grow_halt_poll_ns() does and set halt_poll_ns to 0 as soon as new shrink-ed halt_poll_ns value falls below halt_poll_ns_grow_start.
Message-Id: <[email protected]>
--- virt/kvm/kvm_main.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)
virt/kvm/kvm_main.c +5 -1
@@ -2470,15 +2470,19 @@ static void grow_halt_poll_ns(struct kvm_vcpu *vcpu)static void shrink_halt_poll_ns (struct kvm_vcpu *vcpu) { -unsigned int old, val, shrink; +unsigned int old, val, shrink, grow_start; old = val = vcpu->halt_poll_ns; shrink =READ_ONCE (halt_poll_ns_shrink); + grow_start =READ_ONCE (halt_poll_ns_grow_start);if (shrink ==0 ) val =0 ;else val /= shrink; +if (val < grow_start) + val =0 ; + vcpu->halt_poll_ns = val;trace_kvm_halt_poll_ns_shrink (vcpu->vcpu_id, val, old); }
Signature · 1 line
2.33.0
Re: [PATCH MANUALSEL 5.4 2/4] KVM: do not shrink halt_poll_ns below grow_start
Quoted 55 lines · Sasha Levin
From: Sergey Senozhatsky <[email protected]>
[ Upstream commit
ae232ea460888dc5a8b37e840c553b02521fbf18]
grow_halt_poll_ns()ignores values between 0 andhalt_poll_ns_grow_start(10000 by default). However, when we shrinkhalt_poll_nswe may fall way belowhalt_poll_ns_grow_startand endup withhalt_poll_nsvalues that don't make a lot of sense: like 1 or 9, or 19.VCPU1 trace (
halt_poll_ns_shrinkequals 2):VCPU1 grow 10000
VCPU1 shrink 5000
VCPU1 shrink 2500
VCPU1 shrink 1250
VCPU1 shrink 625
VCPU1 shrink 312
VCPU1 shrink 156
VCPU1 shrink 78
VCPU1 shrink 39
VCPU1 shrink 19
VCPU1 shrink 9
VCPU1 shrink 4Mirror what
grow_halt_poll_ns()does and sethalt_poll_nsto 0 as soon as new shrink-edhalt_poll_nsvalue falls belowhalt_poll_ns_grow_start.Signed-off-by Sergey Senozhatsky <[email protected]>Signed-off-by Paolo Bonzini <[email protected]>Message-Id: <[email protected]>
Signed-off-by Paolo Bonzini <[email protected]>Signed-off-by Sasha Levin <[email protected]>--- virt/kvm/kvm_main.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)virt/kvm/kvm_main.c +2
-1@@ -2470,15 +2470,19 @@ static void grow_halt_poll_ns(struct kvm_vcpu *vcpu)static void shrink_halt_poll_ns (struct kvm_vcpu *vcpu) { -unsigned int old, val, shrink; +unsigned int old, val, shrink, grow_start; old = val = vcpu->halt_poll_ns; shrink =READ_ONCE (halt_poll_ns_shrink); + grow_start =READ_ONCE (halt_poll_ns_grow_start);if (shrink ==0 )
virt/kvm/kvm_main.c static void grow_halt_poll_ns(struct kvm_vcpu *vcpu) · line 2488
Quoted 10 lines
virt/kvm/kvm_main.c +3
-0val =0 ; else val /= shrink; +if (val < grow_start) + val =0 ; + vcpu->halt_poll_ns = val;trace_kvm_halt_poll_ns_shrink (vcpu->vcpu_id, val, old); }
Sasha Levin
maintainerPATCH 3/4 kvm: x86: Add AMD PMU MSRs to msrs_to_save_all[]
In reply to Sasha LevinFrom: Fares Mehanna <[email protected]>
[ Upstream commit e1fc1553cd78292ab3521c94c9dd6e3e70e606a1 ]
Intel PMU MSRs is in msrs_to_save_all[], so add AMD PMU MSRs to have a consistent behavior between Intel and AMD when using KVM_GET_MSRS, KVM_SET_MSRS or KVM_GET_MSR_INDEX_LIST.
We have to add legacy and new MSRs to handle guests running without X86_FEATURE_PERFCTR_CORE.
Message-Id: <[email protected]>
--- arch/x86/kvm/x86.c | 7 +++++++ 1 file changed, 7 insertions(+)
arch/x86/kvm/x86.c +7 -0
@@ -1239,6 +1239,13 @@ static const u32 msrs_to_save_all[] = {MSR_ARCH_PERFMON_EVENTSEL0 +12 ,MSR_ARCH_PERFMON_EVENTSEL0 +13 ,MSR_ARCH_PERFMON_EVENTSEL0 +14 ,MSR_ARCH_PERFMON_EVENTSEL0 +15 ,MSR_ARCH_PERFMON_EVENTSEL0 +16 ,MSR_ARCH_PERFMON_EVENTSEL0 +17 , + +MSR_K7_EVNTSEL0 ,MSR_K7_EVNTSEL1 ,MSR_K7_EVNTSEL2 ,MSR_K7_EVNTSEL3 , +MSR_K7_PERFCTR0 ,MSR_K7_PERFCTR1 ,MSR_K7_PERFCTR2 ,MSR_K7_PERFCTR3 , +MSR_F15H_PERF_CTL0 ,MSR_F15H_PERF_CTL1 ,MSR_F15H_PERF_CTL2 , +MSR_F15H_PERF_CTL3 ,MSR_F15H_PERF_CTL4 ,MSR_F15H_PERF_CTL5 , +MSR_F15H_PERF_CTR0 ,MSR_F15H_PERF_CTR1 ,MSR_F15H_PERF_CTR2 , + MSR_F15H_PERF_CTR3, MSR_F15H_PERF_CTR4, MSR_F15H_PERF_CTR5, };static u32 msrs_to_save[ARRAY_SIZE (msrs_to_save_all)];
Signature · 1 line
2.33.0
Re: [PATCH MANUALSEL 5.4 3/4] kvm: x86: Add AMD PMU MSRs to msrs_to_save_all[]
Quoted 28 lines · Sasha Levin
From: Fares Mehanna <[email protected]>
[ Upstream commit
e1fc1553cd78292ab3521c94c9dd6e3e70e606a1]Intel PMU MSRs is in msrs_to_save_all[], so add AMD PMU MSRs to have a consistent behavior between Intel and AMD when using
KVM_GET_MSRS,KVM_SET_MSRSorKVM_GET_MSR_INDEX_LIST.We have to add legacy and new MSRs to handle guests running without
X86_FEATURE_PERFCTR_CORE.Signed-off-by Fares Mehanna <[email protected]>Message-Id: <[email protected]>
Signed-off-by Paolo Bonzini <[email protected]>Signed-off-by Sasha Levin <[email protected]>--- arch/x86/kvm/x86.c | 7 +++++++ 1 file changed, 7 insertions(+)arch/x86/kvm/x86.c +0
-0@@ -1239,6 +1239,13 @@ static const u32 msrs_to_save_all[] = {MSR_ARCH_PERFMON_EVENTSEL0 +12 ,MSR_ARCH_PERFMON_EVENTSEL0 +13 ,MSR_ARCH_PERFMON_EVENTSEL0 +14 ,MSR_ARCH_PERFMON_EVENTSEL0 +15 , MSR_ARCH_PERFMON_EVENTSEL0 + 16, MSR_ARCH_PERFMON_EVENTSEL0 + 17,
arch/x86/kvm/x86.c static const u32 msrs_to_save_all[] = { · line 1251
Quoted 10 lines
arch/x86/kvm/x86.c +7
-0+ +MSR_K7_EVNTSEL0 ,MSR_K7_EVNTSEL1 ,MSR_K7_EVNTSEL2 ,MSR_K7_EVNTSEL3 , +MSR_K7_PERFCTR0 ,MSR_K7_PERFCTR1 ,MSR_K7_PERFCTR2 ,MSR_K7_PERFCTR3 , +MSR_F15H_PERF_CTL0 ,MSR_F15H_PERF_CTL1 ,MSR_F15H_PERF_CTL2 , +MSR_F15H_PERF_CTL3 ,MSR_F15H_PERF_CTL4 ,MSR_F15H_PERF_CTL5 , +MSR_F15H_PERF_CTR0 ,MSR_F15H_PERF_CTR1 ,MSR_F15H_PERF_CTR2 , + MSR_F15H_PERF_CTR3, MSR_F15H_PERF_CTR4, MSR_F15H_PERF_CTR5, };static u32 msrs_to_save[ARRAY_SIZE (msrs_to_save_all)];
Sasha Levin
maintainerPATCH 4/4 ALSA: pcsp: Make hrtimer forwarding more robust
In reply to Sasha LevinFrom: Thomas Gleixner <[email protected]>
[ Upstream commit f2ff7147c6834f244b8ce636b12e71a3bd044629 ]
The hrtimer callback pcsp_do_timer() prepares rearming of the timer with hrtimer_forward(). hrtimer_forward() is intended to provide a mechanism to forward the expiry time of the hrtimer by a multiple of the period argument so that the expiry time greater than the time provided in the 'now' argument.
pcsp_do_timer() invokes hrtimer_forward() with the current timer expiry time as 'now' argument. That's providing a periodic timer expiry, but is not really robust when the timer callback is delayed so that the resulting new expiry time is already in the past which causes the callback to be invoked immediately again. If the timer is delayed then the back to back invocation is not really making it better than skipping the missed periods. Sound is distorted in any case.
Use hrtimer_forward_now() which ensures that the next expiry is in the future. This prevents hogging the CPU in the timer expiry code and allows later on to remove hrtimer_forward() from the public interfaces.
--- sound/drivers/pcsp/pcsp_lib.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
sound/drivers/pcsp/pcsp_lib.c +1 -1
@@ -145,7 +145,7 @@ enum hrtimer_restart pcsp_do_timer(struct hrtimer *handle)if (pointer_update)pcsp_pointer_update (chip); -hrtimer_forward (handle,hrtimer_get_expires (handle),ns_to_ktime (ns)); +hrtimer_forward_now (handle,ns_to_ktime (ns));return HRTIMER_RESTART ; }
Signature · 1 line
2.33.0
Quoted 75 lines · Sasha Levin
From: Haimin Zhang <[email protected]>
[ Upstream commit
eb7511bf9182292ef1df1082d23039e856d1ddfb]Check the return of
init_srcu_struct(), which can fail due to OOM, when initializing the page track mechanism. Lack of checking leads to a NULL pointer deref found by a modified syzkaller.Reported-by TCS Robot <[email protected]>Signed-off-by Haimin Zhang <[email protected]>Message-Id: <[email protected]>
[Move the call towards the beginning of kvm_arch_init_vm. - Paolo]Signed-off-by Paolo Bonzini <[email protected]>Signed-off-by Sasha Levin <[email protected]>--- arch/x86/include/asm/kvm_page_track.h | 2 +- arch/x86/kvm/page_track.c | 4 ++-- arch/x86/kvm/x86.c | 7 ++++++- 3 files changed, 9 insertions(+), 4 deletions(-)arch/x86/include/asm/kvm_page_track.h +1
-1@@ -46,7 +46,7 @@ struct kvm_page_track_notifier_node { struct kvm_page_track_notifier_node *node); }; -void kvm_page_track_init (struct kvm *kvm); +int kvm_page_track_init (struct kvm *kvm);void kvm_page_track_cleanup (struct kvm *kvm); void kvm_page_track_free_memslot(struct kvm_memory_slot *free,arch/x86/kvm/page_track.c +2
-2@@ -167,13 +167,13 @@ void kvm_page_track_cleanup(struct kvm *kvm)cleanup_srcu_struct (&head->track_srcu); } -void kvm_page_track_init (struct kvm *kvm) +int kvm_page_track_init (struct kvm *kvm) {struct kvm_page_track_notifier_head *head; head = &kvm->arch.track_notifier_head; -init_srcu_struct (&head->track_srcu);INIT_HLIST_HEAD (&head->track_notifier_list); +return init_srcu_struct (&head->track_srcu); }/* arch/x86/kvm/x86.c +6
-0@@ -9585,9 +9585,15 @@ void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu)int kvm_arch_init_vm (struct kvm *kvm,unsigned long type) { +int ret; +if (type)return -EINVAL ; + ret =kvm_page_track_init (kvm); +if (ret) +return ret; +INIT_HLIST_HEAD (&kvm->arch.mask_notifier_list);INIT_LIST_HEAD (&kvm->arch.active_mmu_pages);INIT_LIST_HEAD (&kvm->arch.zapped_obsolete_pages);
arch/x86/kvm/x86.c int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) · line 9625
Quoted 7 lines
arch/x86/kvm/x86.c +0
-1@@ -9614,7 +9620,6 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type)INIT_DELAYED_WORK (&kvm->arch.kvmclock_sync_work, kvmclock_sync_fn);kvm_hv_init_vm (kvm); -kvm_page_track_init (kvm);kvm_mmu_init_vm (kvm);return kvm_x86_ops->vm_init (kvm);