September 2021 - Linux-stable-mirror

FAILED: patch "[PATCH] io-wq: fix race between adding work and activating a free" failed to apply to 5.13-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.13-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 94ffb0a282872c2f4b14f757fa1aef2302aeaabb Mon Sep 17 00:00:00 2001 From: Jens Axboe <axboe(a)kernel.dk> Date: Mon, 30 Aug 2021 11:55:22 -0600 Subject: [PATCH] io-wq: fix race between adding work and activating a free worker The attempt to find and activate a free worker for new work is currently combined with creating a new one if we don't find one, but that opens io-wq up to a race where the worker that is found and activated can put itself to sleep without knowing that it has been selected to perform this new work. Fix this by moving the activation into where we add the new work item, then we can retain it within the wqe->lock scope and elimiate the race with the worker itself checking inside the lock, but sleeping outside of it. Cc: stable(a)vger.kernel.org Reported-by: Andres Freund <andres(a)anarazel.de> Signed-off-by: Jens Axboe <axboe(a)kernel.dk> diff --git a/fs/io-wq.c b/fs/io-wq.c index cd9bd095fb1b..94f8f2ecb8e5 100644 --- a/fs/io-wq.c +++ b/fs/io-wq.c @@ -236,9 +236,9 @@ static bool io_wqe_activate_free_worker(struct io_wqe *wqe) * We need a worker. If we find a free one, we're good. If not, and we're * below the max number of workers, create one. */ -static void io_wqe_wake_worker(struct io_wqe *wqe, struct io_wqe_acct *acct) +static void io_wqe_create_worker(struct io_wqe *wqe, struct io_wqe_acct *acct) { - bool ret; + bool do_create = false, first = false; /* * Most likely an attempt to queue unbounded work on an io_wq that @@ -247,26 +247,18 @@ static void io_wqe_wake_worker(struct io_wqe *wqe, struct io_wqe_acct *acct) if (unlikely(!acct->max_workers)) pr_warn_once("io-wq is not configured for unbound workers"); - rcu_read_lock(); - ret = io_wqe_activate_free_worker(wqe); - rcu_read_unlock(); - - if (!ret) { - bool do_create = false, first = false; - - raw_spin_lock(&wqe->lock); - if (acct->nr_workers < acct->max_workers) { - if (!acct->nr_workers) - first = true; - acct->nr_workers++; - do_create = true; - } - raw_spin_unlock(&wqe->lock); - if (do_create) { - atomic_inc(&acct->nr_running); - atomic_inc(&wqe->wq->worker_refs); - create_io_worker(wqe->wq, wqe, acct->index, first); - } + raw_spin_lock(&wqe->lock); + if (acct->nr_workers < acct->max_workers) { + if (!acct->nr_workers) + first = true; + acct->nr_workers++; + do_create = true; + } + raw_spin_unlock(&wqe->lock); + if (do_create) { + atomic_inc(&acct->nr_running); + atomic_inc(&wqe->wq->worker_refs); + create_io_worker(wqe->wq, wqe, acct->index, first); } } @@ -794,7 +786,8 @@ static void io_wqe_insert_work(struct io_wqe *wqe, struct io_wq_work *work) static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work) { struct io_wqe_acct *acct = io_work_get_acct(wqe, work); - bool do_wake; + unsigned work_flags = work->flags; + bool do_create; /* * If io-wq is exiting for this task, or if the request has explicitly @@ -809,12 +802,16 @@ static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work) raw_spin_lock(&wqe->lock); io_wqe_insert_work(wqe, work); wqe->flags &= ~IO_WQE_FLAG_STALLED; - do_wake = (work->flags & IO_WQ_WORK_CONCURRENT) || - !atomic_read(&acct->nr_running); + + rcu_read_lock(); + do_create = !io_wqe_activate_free_worker(wqe); + rcu_read_unlock(); + raw_spin_unlock(&wqe->lock); - if (do_wake) - io_wqe_wake_worker(wqe, acct); + if (do_create && ((work_flags & IO_WQ_WORK_CONCURRENT) || + !atomic_read(&acct->nr_running))) + io_wqe_create_worker(wqe, acct); } void io_wq_enqueue(struct io_wq *wq, struct io_wq_work *work)

3 years, 4 months

1
0
0 0

FAILED: patch "[PATCH] io-wq: fix wakeup race when adding new work" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 87df7fb922d18e96992aa5e824aa34b2065fef59 Mon Sep 17 00:00:00 2001 From: Jens Axboe <axboe(a)kernel.dk> Date: Mon, 30 Aug 2021 07:45:47 -0600 Subject: [PATCH] io-wq: fix wakeup race when adding new work When new work is added, io_wqe_enqueue() checks if we need to wake or create a new worker. But that check is done outside the lock that otherwise synchronizes us with a worker going to sleep, so we can end up in the following situation: CPU0 CPU1 lock insert work unlock atomic_read(nr_running) != 0 lock atomic_dec(nr_running) no wakeup needed Hold the wqe lock around the "need to wakeup" check. Then we can also get rid of the temporary work_flags variable, as we know the work will remain valid as long as we hold the lock. Cc: stable(a)vger.kernel.org Reported-by: Andres Freund <andres(a)anarazel.de> Signed-off-by: Jens Axboe <axboe(a)kernel.dk> diff --git a/fs/io-wq.c b/fs/io-wq.c index 13aeb48a0964..cd9bd095fb1b 100644 --- a/fs/io-wq.c +++ b/fs/io-wq.c @@ -794,7 +794,7 @@ static void io_wqe_insert_work(struct io_wqe *wqe, struct io_wq_work *work) static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work) { struct io_wqe_acct *acct = io_work_get_acct(wqe, work); - int work_flags; + bool do_wake; /* * If io-wq is exiting for this task, or if the request has explicitly @@ -806,14 +806,14 @@ static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work) return; } - work_flags = work->flags; raw_spin_lock(&wqe->lock); io_wqe_insert_work(wqe, work); wqe->flags &= ~IO_WQE_FLAG_STALLED; + do_wake = (work->flags & IO_WQ_WORK_CONCURRENT) || + !atomic_read(&acct->nr_running); raw_spin_unlock(&wqe->lock); - if ((work_flags & IO_WQ_WORK_CONCURRENT) || - !atomic_read(&acct->nr_running)) + if (do_wake) io_wqe_wake_worker(wqe, acct); }

3 years, 4 months

1
0
0 0

FAILED: patch "[PATCH] io-wq: fix wakeup race when adding new work" failed to apply to 5.13-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.13-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 87df7fb922d18e96992aa5e824aa34b2065fef59 Mon Sep 17 00:00:00 2001 From: Jens Axboe <axboe(a)kernel.dk> Date: Mon, 30 Aug 2021 07:45:47 -0600 Subject: [PATCH] io-wq: fix wakeup race when adding new work When new work is added, io_wqe_enqueue() checks if we need to wake or create a new worker. But that check is done outside the lock that otherwise synchronizes us with a worker going to sleep, so we can end up in the following situation: CPU0 CPU1 lock insert work unlock atomic_read(nr_running) != 0 lock atomic_dec(nr_running) no wakeup needed Hold the wqe lock around the "need to wakeup" check. Then we can also get rid of the temporary work_flags variable, as we know the work will remain valid as long as we hold the lock. Cc: stable(a)vger.kernel.org Reported-by: Andres Freund <andres(a)anarazel.de> Signed-off-by: Jens Axboe <axboe(a)kernel.dk> diff --git a/fs/io-wq.c b/fs/io-wq.c index 13aeb48a0964..cd9bd095fb1b 100644 --- a/fs/io-wq.c +++ b/fs/io-wq.c @@ -794,7 +794,7 @@ static void io_wqe_insert_work(struct io_wqe *wqe, struct io_wq_work *work) static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work) { struct io_wqe_acct *acct = io_work_get_acct(wqe, work); - int work_flags; + bool do_wake; /* * If io-wq is exiting for this task, or if the request has explicitly @@ -806,14 +806,14 @@ static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work) return; } - work_flags = work->flags; raw_spin_lock(&wqe->lock); io_wqe_insert_work(wqe, work); wqe->flags &= ~IO_WQE_FLAG_STALLED; + do_wake = (work->flags & IO_WQ_WORK_CONCURRENT) || + !atomic_read(&acct->nr_running); raw_spin_unlock(&wqe->lock); - if ((work_flags & IO_WQ_WORK_CONCURRENT) || - !atomic_read(&acct->nr_running)) + if (do_wake) io_wqe_wake_worker(wqe, acct); }

3 years, 4 months

1
0
0 0

FAILED: patch "[PATCH] io-wq: fix wakeup race when adding new work" failed to apply to 5.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 87df7fb922d18e96992aa5e824aa34b2065fef59 Mon Sep 17 00:00:00 2001 From: Jens Axboe <axboe(a)kernel.dk> Date: Mon, 30 Aug 2021 07:45:47 -0600 Subject: [PATCH] io-wq: fix wakeup race when adding new work When new work is added, io_wqe_enqueue() checks if we need to wake or create a new worker. But that check is done outside the lock that otherwise synchronizes us with a worker going to sleep, so we can end up in the following situation: CPU0 CPU1 lock insert work unlock atomic_read(nr_running) != 0 lock atomic_dec(nr_running) no wakeup needed Hold the wqe lock around the "need to wakeup" check. Then we can also get rid of the temporary work_flags variable, as we know the work will remain valid as long as we hold the lock. Cc: stable(a)vger.kernel.org Reported-by: Andres Freund <andres(a)anarazel.de> Signed-off-by: Jens Axboe <axboe(a)kernel.dk> diff --git a/fs/io-wq.c b/fs/io-wq.c index 13aeb48a0964..cd9bd095fb1b 100644 --- a/fs/io-wq.c +++ b/fs/io-wq.c @@ -794,7 +794,7 @@ static void io_wqe_insert_work(struct io_wqe *wqe, struct io_wq_work *work) static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work) { struct io_wqe_acct *acct = io_work_get_acct(wqe, work); - int work_flags; + bool do_wake; /* * If io-wq is exiting for this task, or if the request has explicitly @@ -806,14 +806,14 @@ static void io_wqe_enqueue(struct io_wqe *wqe, struct io_wq_work *work) return; } - work_flags = work->flags; raw_spin_lock(&wqe->lock); io_wqe_insert_work(wqe, work); wqe->flags &= ~IO_WQE_FLAG_STALLED; + do_wake = (work->flags & IO_WQ_WORK_CONCURRENT) || + !atomic_read(&acct->nr_running); raw_spin_unlock(&wqe->lock); - if ((work_flags & IO_WQ_WORK_CONCURRENT) || - !atomic_read(&acct->nr_running)) + if (do_wake) io_wqe_wake_worker(wqe, acct); }

3 years, 4 months

1
0
0 0

FAILED: patch "[PATCH] KVM: arm64: vgic: Resample HW pending state on deactivation" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 3134cc8beb69d0db9de651081707c4651c011621 Mon Sep 17 00:00:00 2001 From: Marc Zyngier <maz(a)kernel.org> Date: Thu, 19 Aug 2021 19:03:05 +0100 Subject: [PATCH] KVM: arm64: vgic: Resample HW pending state on deactivation When a mapped level interrupt (a timer, for example) is deactivated by the guest, the corresponding host interrupt is equally deactivated. However, the fate of the pending state still needs to be dealt with in SW. This is specially true when the interrupt was in the active+pending state in the virtual distributor at the point where the guest was entered. On exit, the pending state is potentially stale (the guest may have put the interrupt in a non-pending state). If we don't do anything, the interrupt will be spuriously injected in the guest. Although this shouldn't have any ill effect (spurious interrupts are always possible), we can improve the emulation by detecting the deactivation-while-pending case and resample the interrupt. While we're at it, move the logic into a common helper that can be shared between the two GIC implementations. Fixes: e40cc57bac79 ("KVM: arm/arm64: vgic: Support level-triggered mapped interrupts") Reported-by: Raghavendra Rao Ananta <rananta(a)google.com> Tested-by: Raghavendra Rao Ananta <rananta(a)google.com> Reviewed-by: Oliver Upton <oupton(a)google.com> Signed-off-by: Marc Zyngier <maz(a)kernel.org> Cc: stable(a)vger.kernel.org Link: https://lore.kernel.org/r/20210819180305.1670525-1-maz@kernel.org diff --git a/arch/arm64/kvm/vgic/vgic-v2.c b/arch/arm64/kvm/vgic/vgic-v2.c index 2c580204f1dc..95a18cec14a3 100644 --- a/arch/arm64/kvm/vgic/vgic-v2.c +++ b/arch/arm64/kvm/vgic/vgic-v2.c @@ -60,6 +60,7 @@ void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu) u32 val = cpuif->vgic_lr[lr]; u32 cpuid, intid = val & GICH_LR_VIRTUALID; struct vgic_irq *irq; + bool deactivated; /* Extract the source vCPU id from the LR */ cpuid = val & GICH_LR_PHYSID_CPUID; @@ -75,7 +76,8 @@ void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu) raw_spin_lock(&irq->irq_lock); - /* Always preserve the active bit */ + /* Always preserve the active bit, note deactivation */ + deactivated = irq->active && !(val & GICH_LR_ACTIVE_BIT); irq->active = !!(val & GICH_LR_ACTIVE_BIT); if (irq->active && vgic_irq_is_sgi(intid)) @@ -96,36 +98,8 @@ void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu) if (irq->config == VGIC_CONFIG_LEVEL && !(val & GICH_LR_STATE)) irq->pending_latch = false; - /* - * Level-triggered mapped IRQs are special because we only - * observe rising edges as input to the VGIC. - * - * If the guest never acked the interrupt we have to sample - * the physical line and set the line level, because the - * device state could have changed or we simply need to - * process the still pending interrupt later. - * - * If this causes us to lower the level, we have to also clear - * the physical active state, since we will otherwise never be - * told when the interrupt becomes asserted again. - * - * Another case is when the interrupt requires a helping hand - * on deactivation (no HW deactivation, for example). - */ - if (vgic_irq_is_mapped_level(irq)) { - bool resample = false; - - if (val & GICH_LR_PENDING_BIT) { - irq->line_level = vgic_get_phys_line_level(irq); - resample = !irq->line_level; - } else if (vgic_irq_needs_resampling(irq) && - !(irq->active || irq->pending_latch)) { - resample = true; - } - - if (resample) - vgic_irq_set_phys_active(irq, false); - } + /* Handle resampling for mapped interrupts if required */ + vgic_irq_handle_resampling(irq, deactivated, val & GICH_LR_PENDING_BIT); raw_spin_unlock(&irq->irq_lock); vgic_put_irq(vcpu->kvm, irq); diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c index 66004f61cd83..21a6207fb2ee 100644 --- a/arch/arm64/kvm/vgic/vgic-v3.c +++ b/arch/arm64/kvm/vgic/vgic-v3.c @@ -46,6 +46,7 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu) u32 intid, cpuid; struct vgic_irq *irq; bool is_v2_sgi = false; + bool deactivated; cpuid = val & GICH_LR_PHYSID_CPUID; cpuid >>= GICH_LR_PHYSID_CPUID_SHIFT; @@ -68,7 +69,8 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu) raw_spin_lock(&irq->irq_lock); - /* Always preserve the active bit */ + /* Always preserve the active bit, note deactivation */ + deactivated = irq->active && !(val & ICH_LR_ACTIVE_BIT); irq->active = !!(val & ICH_LR_ACTIVE_BIT); if (irq->active && is_v2_sgi) @@ -89,36 +91,8 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu) if (irq->config == VGIC_CONFIG_LEVEL && !(val & ICH_LR_STATE)) irq->pending_latch = false; - /* - * Level-triggered mapped IRQs are special because we only - * observe rising edges as input to the VGIC. - * - * If the guest never acked the interrupt we have to sample - * the physical line and set the line level, because the - * device state could have changed or we simply need to - * process the still pending interrupt later. - * - * If this causes us to lower the level, we have to also clear - * the physical active state, since we will otherwise never be - * told when the interrupt becomes asserted again. - * - * Another case is when the interrupt requires a helping hand - * on deactivation (no HW deactivation, for example). - */ - if (vgic_irq_is_mapped_level(irq)) { - bool resample = false; - - if (val & ICH_LR_PENDING_BIT) { - irq->line_level = vgic_get_phys_line_level(irq); - resample = !irq->line_level; - } else if (vgic_irq_needs_resampling(irq) && - !(irq->active || irq->pending_latch)) { - resample = true; - } - - if (resample) - vgic_irq_set_phys_active(irq, false); - } + /* Handle resampling for mapped interrupts if required */ + vgic_irq_handle_resampling(irq, deactivated, val & ICH_LR_PENDING_BIT); raw_spin_unlock(&irq->irq_lock); vgic_put_irq(vcpu->kvm, irq); diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c index 81cec508d413..5dad4996cfb2 100644 --- a/arch/arm64/kvm/vgic/vgic.c +++ b/arch/arm64/kvm/vgic/vgic.c @@ -1021,3 +1021,41 @@ bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, unsigned int vintid) return map_is_active; } + +/* + * Level-triggered mapped IRQs are special because we only observe rising + * edges as input to the VGIC. + * + * If the guest never acked the interrupt we have to sample the physical + * line and set the line level, because the device state could have changed + * or we simply need to process the still pending interrupt later. + * + * We could also have entered the guest with the interrupt active+pending. + * On the next exit, we need to re-evaluate the pending state, as it could + * otherwise result in a spurious interrupt by injecting a now potentially + * stale pending state. + * + * If this causes us to lower the level, we have to also clear the physical + * active state, since we will otherwise never be told when the interrupt + * becomes asserted again. + * + * Another case is when the interrupt requires a helping hand on + * deactivation (no HW deactivation, for example). + */ +void vgic_irq_handle_resampling(struct vgic_irq *irq, + bool lr_deactivated, bool lr_pending) +{ + if (vgic_irq_is_mapped_level(irq)) { + bool resample = false; + + if (unlikely(vgic_irq_needs_resampling(irq))) { + resample = !(irq->active || irq->pending_latch); + } else if (lr_pending || (lr_deactivated && irq->line_level)) { + irq->line_level = vgic_get_phys_line_level(irq); + resample = !irq->line_level; + } + + if (resample) + vgic_irq_set_phys_active(irq, false); + } +} diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h index dc1f3d1657ee..14a9218641f5 100644 --- a/arch/arm64/kvm/vgic/vgic.h +++ b/arch/arm64/kvm/vgic/vgic.h @@ -169,6 +169,8 @@ void vgic_irq_set_phys_active(struct vgic_irq *irq, bool active); bool vgic_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq, unsigned long flags); void vgic_kick_vcpus(struct kvm *kvm); +void vgic_irq_handle_resampling(struct vgic_irq *irq, + bool lr_deactivated, bool lr_pending); int vgic_check_ioaddr(struct kvm *kvm, phys_addr_t *ioaddr, phys_addr_t addr, phys_addr_t alignment);

3 years, 4 months

1
0
0 0

FAILED: patch "[PATCH] KVM: arm64: vgic: Resample HW pending state on deactivation" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 3134cc8beb69d0db9de651081707c4651c011621 Mon Sep 17 00:00:00 2001 From: Marc Zyngier <maz(a)kernel.org> Date: Thu, 19 Aug 2021 19:03:05 +0100 Subject: [PATCH] KVM: arm64: vgic: Resample HW pending state on deactivation When a mapped level interrupt (a timer, for example) is deactivated by the guest, the corresponding host interrupt is equally deactivated. However, the fate of the pending state still needs to be dealt with in SW. This is specially true when the interrupt was in the active+pending state in the virtual distributor at the point where the guest was entered. On exit, the pending state is potentially stale (the guest may have put the interrupt in a non-pending state). If we don't do anything, the interrupt will be spuriously injected in the guest. Although this shouldn't have any ill effect (spurious interrupts are always possible), we can improve the emulation by detecting the deactivation-while-pending case and resample the interrupt. While we're at it, move the logic into a common helper that can be shared between the two GIC implementations. Fixes: e40cc57bac79 ("KVM: arm/arm64: vgic: Support level-triggered mapped interrupts") Reported-by: Raghavendra Rao Ananta <rananta(a)google.com> Tested-by: Raghavendra Rao Ananta <rananta(a)google.com> Reviewed-by: Oliver Upton <oupton(a)google.com> Signed-off-by: Marc Zyngier <maz(a)kernel.org> Cc: stable(a)vger.kernel.org Link: https://lore.kernel.org/r/20210819180305.1670525-1-maz@kernel.org diff --git a/arch/arm64/kvm/vgic/vgic-v2.c b/arch/arm64/kvm/vgic/vgic-v2.c index 2c580204f1dc..95a18cec14a3 100644 --- a/arch/arm64/kvm/vgic/vgic-v2.c +++ b/arch/arm64/kvm/vgic/vgic-v2.c @@ -60,6 +60,7 @@ void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu) u32 val = cpuif->vgic_lr[lr]; u32 cpuid, intid = val & GICH_LR_VIRTUALID; struct vgic_irq *irq; + bool deactivated; /* Extract the source vCPU id from the LR */ cpuid = val & GICH_LR_PHYSID_CPUID; @@ -75,7 +76,8 @@ void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu) raw_spin_lock(&irq->irq_lock); - /* Always preserve the active bit */ + /* Always preserve the active bit, note deactivation */ + deactivated = irq->active && !(val & GICH_LR_ACTIVE_BIT); irq->active = !!(val & GICH_LR_ACTIVE_BIT); if (irq->active && vgic_irq_is_sgi(intid)) @@ -96,36 +98,8 @@ void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu) if (irq->config == VGIC_CONFIG_LEVEL && !(val & GICH_LR_STATE)) irq->pending_latch = false; - /* - * Level-triggered mapped IRQs are special because we only - * observe rising edges as input to the VGIC. - * - * If the guest never acked the interrupt we have to sample - * the physical line and set the line level, because the - * device state could have changed or we simply need to - * process the still pending interrupt later. - * - * If this causes us to lower the level, we have to also clear - * the physical active state, since we will otherwise never be - * told when the interrupt becomes asserted again. - * - * Another case is when the interrupt requires a helping hand - * on deactivation (no HW deactivation, for example). - */ - if (vgic_irq_is_mapped_level(irq)) { - bool resample = false; - - if (val & GICH_LR_PENDING_BIT) { - irq->line_level = vgic_get_phys_line_level(irq); - resample = !irq->line_level; - } else if (vgic_irq_needs_resampling(irq) && - !(irq->active || irq->pending_latch)) { - resample = true; - } - - if (resample) - vgic_irq_set_phys_active(irq, false); - } + /* Handle resampling for mapped interrupts if required */ + vgic_irq_handle_resampling(irq, deactivated, val & GICH_LR_PENDING_BIT); raw_spin_unlock(&irq->irq_lock); vgic_put_irq(vcpu->kvm, irq); diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c index 66004f61cd83..21a6207fb2ee 100644 --- a/arch/arm64/kvm/vgic/vgic-v3.c +++ b/arch/arm64/kvm/vgic/vgic-v3.c @@ -46,6 +46,7 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu) u32 intid, cpuid; struct vgic_irq *irq; bool is_v2_sgi = false; + bool deactivated; cpuid = val & GICH_LR_PHYSID_CPUID; cpuid >>= GICH_LR_PHYSID_CPUID_SHIFT; @@ -68,7 +69,8 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu) raw_spin_lock(&irq->irq_lock); - /* Always preserve the active bit */ + /* Always preserve the active bit, note deactivation */ + deactivated = irq->active && !(val & ICH_LR_ACTIVE_BIT); irq->active = !!(val & ICH_LR_ACTIVE_BIT); if (irq->active && is_v2_sgi) @@ -89,36 +91,8 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu) if (irq->config == VGIC_CONFIG_LEVEL && !(val & ICH_LR_STATE)) irq->pending_latch = false; - /* - * Level-triggered mapped IRQs are special because we only - * observe rising edges as input to the VGIC. - * - * If the guest never acked the interrupt we have to sample - * the physical line and set the line level, because the - * device state could have changed or we simply need to - * process the still pending interrupt later. - * - * If this causes us to lower the level, we have to also clear - * the physical active state, since we will otherwise never be - * told when the interrupt becomes asserted again. - * - * Another case is when the interrupt requires a helping hand - * on deactivation (no HW deactivation, for example). - */ - if (vgic_irq_is_mapped_level(irq)) { - bool resample = false; - - if (val & ICH_LR_PENDING_BIT) { - irq->line_level = vgic_get_phys_line_level(irq); - resample = !irq->line_level; - } else if (vgic_irq_needs_resampling(irq) && - !(irq->active || irq->pending_latch)) { - resample = true; - } - - if (resample) - vgic_irq_set_phys_active(irq, false); - } + /* Handle resampling for mapped interrupts if required */ + vgic_irq_handle_resampling(irq, deactivated, val & ICH_LR_PENDING_BIT); raw_spin_unlock(&irq->irq_lock); vgic_put_irq(vcpu->kvm, irq); diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c index 81cec508d413..5dad4996cfb2 100644 --- a/arch/arm64/kvm/vgic/vgic.c +++ b/arch/arm64/kvm/vgic/vgic.c @@ -1021,3 +1021,41 @@ bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, unsigned int vintid) return map_is_active; } + +/* + * Level-triggered mapped IRQs are special because we only observe rising + * edges as input to the VGIC. + * + * If the guest never acked the interrupt we have to sample the physical + * line and set the line level, because the device state could have changed + * or we simply need to process the still pending interrupt later. + * + * We could also have entered the guest with the interrupt active+pending. + * On the next exit, we need to re-evaluate the pending state, as it could + * otherwise result in a spurious interrupt by injecting a now potentially + * stale pending state. + * + * If this causes us to lower the level, we have to also clear the physical + * active state, since we will otherwise never be told when the interrupt + * becomes asserted again. + * + * Another case is when the interrupt requires a helping hand on + * deactivation (no HW deactivation, for example). + */ +void vgic_irq_handle_resampling(struct vgic_irq *irq, + bool lr_deactivated, bool lr_pending) +{ + if (vgic_irq_is_mapped_level(irq)) { + bool resample = false; + + if (unlikely(vgic_irq_needs_resampling(irq))) { + resample = !(irq->active || irq->pending_latch); + } else if (lr_pending || (lr_deactivated && irq->line_level)) { + irq->line_level = vgic_get_phys_line_level(irq); + resample = !irq->line_level; + } + + if (resample) + vgic_irq_set_phys_active(irq, false); + } +} diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h index dc1f3d1657ee..14a9218641f5 100644 --- a/arch/arm64/kvm/vgic/vgic.h +++ b/arch/arm64/kvm/vgic/vgic.h @@ -169,6 +169,8 @@ void vgic_irq_set_phys_active(struct vgic_irq *irq, bool active); bool vgic_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq, unsigned long flags); void vgic_kick_vcpus(struct kvm *kvm); +void vgic_irq_handle_resampling(struct vgic_irq *irq, + bool lr_deactivated, bool lr_pending); int vgic_check_ioaddr(struct kvm *kvm, phys_addr_t *ioaddr, phys_addr_t addr, phys_addr_t alignment);

3 years, 4 months

1
0
0 0

FAILED: patch "[PATCH] KVM: arm64: vgic: Resample HW pending state on deactivation" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 3134cc8beb69d0db9de651081707c4651c011621 Mon Sep 17 00:00:00 2001 From: Marc Zyngier <maz(a)kernel.org> Date: Thu, 19 Aug 2021 19:03:05 +0100 Subject: [PATCH] KVM: arm64: vgic: Resample HW pending state on deactivation When a mapped level interrupt (a timer, for example) is deactivated by the guest, the corresponding host interrupt is equally deactivated. However, the fate of the pending state still needs to be dealt with in SW. This is specially true when the interrupt was in the active+pending state in the virtual distributor at the point where the guest was entered. On exit, the pending state is potentially stale (the guest may have put the interrupt in a non-pending state). If we don't do anything, the interrupt will be spuriously injected in the guest. Although this shouldn't have any ill effect (spurious interrupts are always possible), we can improve the emulation by detecting the deactivation-while-pending case and resample the interrupt. While we're at it, move the logic into a common helper that can be shared between the two GIC implementations. Fixes: e40cc57bac79 ("KVM: arm/arm64: vgic: Support level-triggered mapped interrupts") Reported-by: Raghavendra Rao Ananta <rananta(a)google.com> Tested-by: Raghavendra Rao Ananta <rananta(a)google.com> Reviewed-by: Oliver Upton <oupton(a)google.com> Signed-off-by: Marc Zyngier <maz(a)kernel.org> Cc: stable(a)vger.kernel.org Link: https://lore.kernel.org/r/20210819180305.1670525-1-maz@kernel.org diff --git a/arch/arm64/kvm/vgic/vgic-v2.c b/arch/arm64/kvm/vgic/vgic-v2.c index 2c580204f1dc..95a18cec14a3 100644 --- a/arch/arm64/kvm/vgic/vgic-v2.c +++ b/arch/arm64/kvm/vgic/vgic-v2.c @@ -60,6 +60,7 @@ void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu) u32 val = cpuif->vgic_lr[lr]; u32 cpuid, intid = val & GICH_LR_VIRTUALID; struct vgic_irq *irq; + bool deactivated; /* Extract the source vCPU id from the LR */ cpuid = val & GICH_LR_PHYSID_CPUID; @@ -75,7 +76,8 @@ void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu) raw_spin_lock(&irq->irq_lock); - /* Always preserve the active bit */ + /* Always preserve the active bit, note deactivation */ + deactivated = irq->active && !(val & GICH_LR_ACTIVE_BIT); irq->active = !!(val & GICH_LR_ACTIVE_BIT); if (irq->active && vgic_irq_is_sgi(intid)) @@ -96,36 +98,8 @@ void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu) if (irq->config == VGIC_CONFIG_LEVEL && !(val & GICH_LR_STATE)) irq->pending_latch = false; - /* - * Level-triggered mapped IRQs are special because we only - * observe rising edges as input to the VGIC. - * - * If the guest never acked the interrupt we have to sample - * the physical line and set the line level, because the - * device state could have changed or we simply need to - * process the still pending interrupt later. - * - * If this causes us to lower the level, we have to also clear - * the physical active state, since we will otherwise never be - * told when the interrupt becomes asserted again. - * - * Another case is when the interrupt requires a helping hand - * on deactivation (no HW deactivation, for example). - */ - if (vgic_irq_is_mapped_level(irq)) { - bool resample = false; - - if (val & GICH_LR_PENDING_BIT) { - irq->line_level = vgic_get_phys_line_level(irq); - resample = !irq->line_level; - } else if (vgic_irq_needs_resampling(irq) && - !(irq->active || irq->pending_latch)) { - resample = true; - } - - if (resample) - vgic_irq_set_phys_active(irq, false); - } + /* Handle resampling for mapped interrupts if required */ + vgic_irq_handle_resampling(irq, deactivated, val & GICH_LR_PENDING_BIT); raw_spin_unlock(&irq->irq_lock); vgic_put_irq(vcpu->kvm, irq); diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c index 66004f61cd83..21a6207fb2ee 100644 --- a/arch/arm64/kvm/vgic/vgic-v3.c +++ b/arch/arm64/kvm/vgic/vgic-v3.c @@ -46,6 +46,7 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu) u32 intid, cpuid; struct vgic_irq *irq; bool is_v2_sgi = false; + bool deactivated; cpuid = val & GICH_LR_PHYSID_CPUID; cpuid >>= GICH_LR_PHYSID_CPUID_SHIFT; @@ -68,7 +69,8 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu) raw_spin_lock(&irq->irq_lock); - /* Always preserve the active bit */ + /* Always preserve the active bit, note deactivation */ + deactivated = irq->active && !(val & ICH_LR_ACTIVE_BIT); irq->active = !!(val & ICH_LR_ACTIVE_BIT); if (irq->active && is_v2_sgi) @@ -89,36 +91,8 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu) if (irq->config == VGIC_CONFIG_LEVEL && !(val & ICH_LR_STATE)) irq->pending_latch = false; - /* - * Level-triggered mapped IRQs are special because we only - * observe rising edges as input to the VGIC. - * - * If the guest never acked the interrupt we have to sample - * the physical line and set the line level, because the - * device state could have changed or we simply need to - * process the still pending interrupt later. - * - * If this causes us to lower the level, we have to also clear - * the physical active state, since we will otherwise never be - * told when the interrupt becomes asserted again. - * - * Another case is when the interrupt requires a helping hand - * on deactivation (no HW deactivation, for example). - */ - if (vgic_irq_is_mapped_level(irq)) { - bool resample = false; - - if (val & ICH_LR_PENDING_BIT) { - irq->line_level = vgic_get_phys_line_level(irq); - resample = !irq->line_level; - } else if (vgic_irq_needs_resampling(irq) && - !(irq->active || irq->pending_latch)) { - resample = true; - } - - if (resample) - vgic_irq_set_phys_active(irq, false); - } + /* Handle resampling for mapped interrupts if required */ + vgic_irq_handle_resampling(irq, deactivated, val & ICH_LR_PENDING_BIT); raw_spin_unlock(&irq->irq_lock); vgic_put_irq(vcpu->kvm, irq); diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c index 81cec508d413..5dad4996cfb2 100644 --- a/arch/arm64/kvm/vgic/vgic.c +++ b/arch/arm64/kvm/vgic/vgic.c @@ -1021,3 +1021,41 @@ bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, unsigned int vintid) return map_is_active; } + +/* + * Level-triggered mapped IRQs are special because we only observe rising + * edges as input to the VGIC. + * + * If the guest never acked the interrupt we have to sample the physical + * line and set the line level, because the device state could have changed + * or we simply need to process the still pending interrupt later. + * + * We could also have entered the guest with the interrupt active+pending. + * On the next exit, we need to re-evaluate the pending state, as it could + * otherwise result in a spurious interrupt by injecting a now potentially + * stale pending state. + * + * If this causes us to lower the level, we have to also clear the physical + * active state, since we will otherwise never be told when the interrupt + * becomes asserted again. + * + * Another case is when the interrupt requires a helping hand on + * deactivation (no HW deactivation, for example). + */ +void vgic_irq_handle_resampling(struct vgic_irq *irq, + bool lr_deactivated, bool lr_pending) +{ + if (vgic_irq_is_mapped_level(irq)) { + bool resample = false; + + if (unlikely(vgic_irq_needs_resampling(irq))) { + resample = !(irq->active || irq->pending_latch); + } else if (lr_pending || (lr_deactivated && irq->line_level)) { + irq->line_level = vgic_get_phys_line_level(irq); + resample = !irq->line_level; + } + + if (resample) + vgic_irq_set_phys_active(irq, false); + } +} diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h index dc1f3d1657ee..14a9218641f5 100644 --- a/arch/arm64/kvm/vgic/vgic.h +++ b/arch/arm64/kvm/vgic/vgic.h @@ -169,6 +169,8 @@ void vgic_irq_set_phys_active(struct vgic_irq *irq, bool active); bool vgic_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq, unsigned long flags); void vgic_kick_vcpus(struct kvm *kvm); +void vgic_irq_handle_resampling(struct vgic_irq *irq, + bool lr_deactivated, bool lr_pending); int vgic_check_ioaddr(struct kvm *kvm, phys_addr_t *ioaddr, phys_addr_t addr, phys_addr_t alignment);

3 years, 4 months

1
0
0 0

FAILED: patch "[PATCH] KVM: arm64: vgic: Resample HW pending state on deactivation" failed to apply to 5.13-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.13-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 3134cc8beb69d0db9de651081707c4651c011621 Mon Sep 17 00:00:00 2001 From: Marc Zyngier <maz(a)kernel.org> Date: Thu, 19 Aug 2021 19:03:05 +0100 Subject: [PATCH] KVM: arm64: vgic: Resample HW pending state on deactivation When a mapped level interrupt (a timer, for example) is deactivated by the guest, the corresponding host interrupt is equally deactivated. However, the fate of the pending state still needs to be dealt with in SW. This is specially true when the interrupt was in the active+pending state in the virtual distributor at the point where the guest was entered. On exit, the pending state is potentially stale (the guest may have put the interrupt in a non-pending state). If we don't do anything, the interrupt will be spuriously injected in the guest. Although this shouldn't have any ill effect (spurious interrupts are always possible), we can improve the emulation by detecting the deactivation-while-pending case and resample the interrupt. While we're at it, move the logic into a common helper that can be shared between the two GIC implementations. Fixes: e40cc57bac79 ("KVM: arm/arm64: vgic: Support level-triggered mapped interrupts") Reported-by: Raghavendra Rao Ananta <rananta(a)google.com> Tested-by: Raghavendra Rao Ananta <rananta(a)google.com> Reviewed-by: Oliver Upton <oupton(a)google.com> Signed-off-by: Marc Zyngier <maz(a)kernel.org> Cc: stable(a)vger.kernel.org Link: https://lore.kernel.org/r/20210819180305.1670525-1-maz@kernel.org diff --git a/arch/arm64/kvm/vgic/vgic-v2.c b/arch/arm64/kvm/vgic/vgic-v2.c index 2c580204f1dc..95a18cec14a3 100644 --- a/arch/arm64/kvm/vgic/vgic-v2.c +++ b/arch/arm64/kvm/vgic/vgic-v2.c @@ -60,6 +60,7 @@ void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu) u32 val = cpuif->vgic_lr[lr]; u32 cpuid, intid = val & GICH_LR_VIRTUALID; struct vgic_irq *irq; + bool deactivated; /* Extract the source vCPU id from the LR */ cpuid = val & GICH_LR_PHYSID_CPUID; @@ -75,7 +76,8 @@ void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu) raw_spin_lock(&irq->irq_lock); - /* Always preserve the active bit */ + /* Always preserve the active bit, note deactivation */ + deactivated = irq->active && !(val & GICH_LR_ACTIVE_BIT); irq->active = !!(val & GICH_LR_ACTIVE_BIT); if (irq->active && vgic_irq_is_sgi(intid)) @@ -96,36 +98,8 @@ void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu) if (irq->config == VGIC_CONFIG_LEVEL && !(val & GICH_LR_STATE)) irq->pending_latch = false; - /* - * Level-triggered mapped IRQs are special because we only - * observe rising edges as input to the VGIC. - * - * If the guest never acked the interrupt we have to sample - * the physical line and set the line level, because the - * device state could have changed or we simply need to - * process the still pending interrupt later. - * - * If this causes us to lower the level, we have to also clear - * the physical active state, since we will otherwise never be - * told when the interrupt becomes asserted again. - * - * Another case is when the interrupt requires a helping hand - * on deactivation (no HW deactivation, for example). - */ - if (vgic_irq_is_mapped_level(irq)) { - bool resample = false; - - if (val & GICH_LR_PENDING_BIT) { - irq->line_level = vgic_get_phys_line_level(irq); - resample = !irq->line_level; - } else if (vgic_irq_needs_resampling(irq) && - !(irq->active || irq->pending_latch)) { - resample = true; - } - - if (resample) - vgic_irq_set_phys_active(irq, false); - } + /* Handle resampling for mapped interrupts if required */ + vgic_irq_handle_resampling(irq, deactivated, val & GICH_LR_PENDING_BIT); raw_spin_unlock(&irq->irq_lock); vgic_put_irq(vcpu->kvm, irq); diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c index 66004f61cd83..21a6207fb2ee 100644 --- a/arch/arm64/kvm/vgic/vgic-v3.c +++ b/arch/arm64/kvm/vgic/vgic-v3.c @@ -46,6 +46,7 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu) u32 intid, cpuid; struct vgic_irq *irq; bool is_v2_sgi = false; + bool deactivated; cpuid = val & GICH_LR_PHYSID_CPUID; cpuid >>= GICH_LR_PHYSID_CPUID_SHIFT; @@ -68,7 +69,8 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu) raw_spin_lock(&irq->irq_lock); - /* Always preserve the active bit */ + /* Always preserve the active bit, note deactivation */ + deactivated = irq->active && !(val & ICH_LR_ACTIVE_BIT); irq->active = !!(val & ICH_LR_ACTIVE_BIT); if (irq->active && is_v2_sgi) @@ -89,36 +91,8 @@ void vgic_v3_fold_lr_state(struct kvm_vcpu *vcpu) if (irq->config == VGIC_CONFIG_LEVEL && !(val & ICH_LR_STATE)) irq->pending_latch = false; - /* - * Level-triggered mapped IRQs are special because we only - * observe rising edges as input to the VGIC. - * - * If the guest never acked the interrupt we have to sample - * the physical line and set the line level, because the - * device state could have changed or we simply need to - * process the still pending interrupt later. - * - * If this causes us to lower the level, we have to also clear - * the physical active state, since we will otherwise never be - * told when the interrupt becomes asserted again. - * - * Another case is when the interrupt requires a helping hand - * on deactivation (no HW deactivation, for example). - */ - if (vgic_irq_is_mapped_level(irq)) { - bool resample = false; - - if (val & ICH_LR_PENDING_BIT) { - irq->line_level = vgic_get_phys_line_level(irq); - resample = !irq->line_level; - } else if (vgic_irq_needs_resampling(irq) && - !(irq->active || irq->pending_latch)) { - resample = true; - } - - if (resample) - vgic_irq_set_phys_active(irq, false); - } + /* Handle resampling for mapped interrupts if required */ + vgic_irq_handle_resampling(irq, deactivated, val & ICH_LR_PENDING_BIT); raw_spin_unlock(&irq->irq_lock); vgic_put_irq(vcpu->kvm, irq); diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c index 81cec508d413..5dad4996cfb2 100644 --- a/arch/arm64/kvm/vgic/vgic.c +++ b/arch/arm64/kvm/vgic/vgic.c @@ -1021,3 +1021,41 @@ bool kvm_vgic_map_is_active(struct kvm_vcpu *vcpu, unsigned int vintid) return map_is_active; } + +/* + * Level-triggered mapped IRQs are special because we only observe rising + * edges as input to the VGIC. + * + * If the guest never acked the interrupt we have to sample the physical + * line and set the line level, because the device state could have changed + * or we simply need to process the still pending interrupt later. + * + * We could also have entered the guest with the interrupt active+pending. + * On the next exit, we need to re-evaluate the pending state, as it could + * otherwise result in a spurious interrupt by injecting a now potentially + * stale pending state. + * + * If this causes us to lower the level, we have to also clear the physical + * active state, since we will otherwise never be told when the interrupt + * becomes asserted again. + * + * Another case is when the interrupt requires a helping hand on + * deactivation (no HW deactivation, for example). + */ +void vgic_irq_handle_resampling(struct vgic_irq *irq, + bool lr_deactivated, bool lr_pending) +{ + if (vgic_irq_is_mapped_level(irq)) { + bool resample = false; + + if (unlikely(vgic_irq_needs_resampling(irq))) { + resample = !(irq->active || irq->pending_latch); + } else if (lr_pending || (lr_deactivated && irq->line_level)) { + irq->line_level = vgic_get_phys_line_level(irq); + resample = !irq->line_level; + } + + if (resample) + vgic_irq_set_phys_active(irq, false); + } +} diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h index dc1f3d1657ee..14a9218641f5 100644 --- a/arch/arm64/kvm/vgic/vgic.h +++ b/arch/arm64/kvm/vgic/vgic.h @@ -169,6 +169,8 @@ void vgic_irq_set_phys_active(struct vgic_irq *irq, bool active); bool vgic_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq, unsigned long flags); void vgic_kick_vcpus(struct kvm *kvm); +void vgic_irq_handle_resampling(struct vgic_irq *irq, + bool lr_deactivated, bool lr_pending); int vgic_check_ioaddr(struct kvm *kvm, phys_addr_t *ioaddr, phys_addr_t addr, phys_addr_t alignment);

3 years, 4 months

1
0
0 0

FAILED: patch "[PATCH] KVM: nVMX: Unconditionally clear nested.pi_pending on nested" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From f7782bb8d818d8f47c26b22079db10599922787a Mon Sep 17 00:00:00 2001 From: Sean Christopherson <seanjc(a)google.com> Date: Tue, 10 Aug 2021 07:45:26 -0700 Subject: [PATCH] KVM: nVMX: Unconditionally clear nested.pi_pending on nested VM-Enter Clear nested.pi_pending on nested VM-Enter even if L2 will run without posted interrupts enabled. If nested.pi_pending is left set from a previous L2, vmx_complete_nested_posted_interrupt() will pick up the stale flag and exit to userspace with an "internal emulation error" due the new L2 not having a valid nested.pi_desc. Arguably, vmx_complete_nested_posted_interrupt() should first check for posted interrupts being enabled, but it's also completely reasonable that KVM wouldn't screw up a fundamental flag. Not to mention that the mere existence of nested.pi_pending is a long-standing bug as KVM shouldn't move the posted interrupt out of the IRR until it's actually processed, e.g. KVM effectively drops an interrupt when it performs a nested VM-Exit with a "pending" posted interrupt. Fixing the mess is a future problem. Prior to vmx_complete_nested_posted_interrupt() interpreting a null PI descriptor as an error, this was a benign bug as the null PI descriptor effectively served as a check on PI not being enabled. Even then, the new flow did not become problematic until KVM started checking the result of kvm_check_nested_events(). Fixes: 705699a13994 ("KVM: nVMX: Enable nested posted interrupt processing") Fixes: 966eefb89657 ("KVM: nVMX: Disable vmcs02 posted interrupts if vmcs12 PID isn't mappable") Fixes: 47d3530f86c0 ("KVM: x86: Exit to userspace when kvm_check_nested_events fails") Cc: stable(a)vger.kernel.org Cc: Jim Mattson <jmattson(a)google.com> Signed-off-by: Sean Christopherson <seanjc(a)google.com> Message-Id: <20210810144526.2662272-1-seanjc(a)google.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 264a9f4c9179..bc6327950657 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2187,12 +2187,11 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct loaded_vmcs *vmcs0 ~PIN_BASED_VMX_PREEMPTION_TIMER); /* Posted interrupts setting is only taken from vmcs12. */ - if (nested_cpu_has_posted_intr(vmcs12)) { + vmx->nested.pi_pending = false; + if (nested_cpu_has_posted_intr(vmcs12)) vmx->nested.posted_intr_nv = vmcs12->posted_intr_nv; - vmx->nested.pi_pending = false; - } else { + else exec_control &= ~PIN_BASED_POSTED_INTR; - } pin_controls_set(vmx, exec_control); /*

3 years, 4 months

1
0
0 0

FAILED: patch "[PATCH] KVM: nVMX: Unconditionally clear nested.pi_pending on nested" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From f7782bb8d818d8f47c26b22079db10599922787a Mon Sep 17 00:00:00 2001 From: Sean Christopherson <seanjc(a)google.com> Date: Tue, 10 Aug 2021 07:45:26 -0700 Subject: [PATCH] KVM: nVMX: Unconditionally clear nested.pi_pending on nested VM-Enter Clear nested.pi_pending on nested VM-Enter even if L2 will run without posted interrupts enabled. If nested.pi_pending is left set from a previous L2, vmx_complete_nested_posted_interrupt() will pick up the stale flag and exit to userspace with an "internal emulation error" due the new L2 not having a valid nested.pi_desc. Arguably, vmx_complete_nested_posted_interrupt() should first check for posted interrupts being enabled, but it's also completely reasonable that KVM wouldn't screw up a fundamental flag. Not to mention that the mere existence of nested.pi_pending is a long-standing bug as KVM shouldn't move the posted interrupt out of the IRR until it's actually processed, e.g. KVM effectively drops an interrupt when it performs a nested VM-Exit with a "pending" posted interrupt. Fixing the mess is a future problem. Prior to vmx_complete_nested_posted_interrupt() interpreting a null PI descriptor as an error, this was a benign bug as the null PI descriptor effectively served as a check on PI not being enabled. Even then, the new flow did not become problematic until KVM started checking the result of kvm_check_nested_events(). Fixes: 705699a13994 ("KVM: nVMX: Enable nested posted interrupt processing") Fixes: 966eefb89657 ("KVM: nVMX: Disable vmcs02 posted interrupts if vmcs12 PID isn't mappable") Fixes: 47d3530f86c0 ("KVM: x86: Exit to userspace when kvm_check_nested_events fails") Cc: stable(a)vger.kernel.org Cc: Jim Mattson <jmattson(a)google.com> Signed-off-by: Sean Christopherson <seanjc(a)google.com> Message-Id: <20210810144526.2662272-1-seanjc(a)google.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index 264a9f4c9179..bc6327950657 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -2187,12 +2187,11 @@ static void prepare_vmcs02_early(struct vcpu_vmx *vmx, struct loaded_vmcs *vmcs0 ~PIN_BASED_VMX_PREEMPTION_TIMER); /* Posted interrupts setting is only taken from vmcs12. */ - if (nested_cpu_has_posted_intr(vmcs12)) { + vmx->nested.pi_pending = false; + if (nested_cpu_has_posted_intr(vmcs12)) vmx->nested.posted_intr_nv = vmcs12->posted_intr_nv; - vmx->nested.pi_pending = false; - } else { + else exec_control &= ~PIN_BASED_POSTED_INTR; - } pin_controls_set(vmx, exec_control); /*

3 years, 4 months

1
0
0 0

2025

2024

2023

2022

2021

2020

2019

2018

2017

Linux-stable-mirror September 2021