[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v8 20/27] ARM: GICv3: handle unmapped LPIs
When LPIs get unmapped by a guest, they might still be in some LR of some VCPU. Nevertheless we remove the corresponding pending_irq (possibly freeing it), and detect this case (irq_to_pending() returns NULL) when the LR gets cleaned up later. However a *new* LPI may get mapped with the same number while the old LPI is *still* in some LR. To avoid getting the wrong state, we mark every newly mapped LPI as PRISTINE, which means: has never been in an LR before. If we detect the LPI in an LR anyway, it must have been an older one, which we can simply retire. Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx> --- xen/arch/arm/gic.c | 17 ++++++++++++++++- xen/arch/arm/vgic-v3-its.c | 5 +++++ xen/include/asm-arm/vgic.h | 1 + 3 files changed, 22 insertions(+), 1 deletion(-) diff --git a/xen/arch/arm/gic.c b/xen/arch/arm/gic.c index d752352..e8c3202 100644 --- a/xen/arch/arm/gic.c +++ b/xen/arch/arm/gic.c @@ -373,6 +373,8 @@ static inline void gic_set_lr(int lr, struct pending_irq *p, { ASSERT(!local_irq_is_enabled()); + clear_bit(GIC_IRQ_GUEST_PRISTINE_LPI, &p->status); + gic_hw_ops->update_lr(lr, p, state); set_bit(GIC_IRQ_GUEST_VISIBLE, &p->status); @@ -510,7 +512,17 @@ static void gic_update_one_lr(struct vcpu *v, int i) } else if ( lr_val.state & GICH_LR_PENDING ) { - int q __attribute__ ((unused)) = test_and_clear_bit(GIC_IRQ_GUEST_QUEUED, &p->status); + int q __attribute__ ((unused)); + + if ( test_and_clear_bit(GIC_IRQ_GUEST_PRISTINE_LPI, &p->status) ) + { + gic_hw_ops->clear_lr(i); + clear_bit(i, &this_cpu(lr_mask)); + + return; + } + + q = test_and_clear_bit(GIC_IRQ_GUEST_QUEUED, &p->status); #ifdef GIC_DEBUG if ( q ) gdprintk(XENLOG_DEBUG, "trying to inject irq=%d into d%dv%d, when it is already pending in LR%d\n", @@ -522,6 +534,9 @@ static void gic_update_one_lr(struct vcpu *v, int i) gic_hw_ops->clear_lr(i); clear_bit(i, &this_cpu(lr_mask)); + if ( test_and_clear_bit(GIC_IRQ_GUEST_PRISTINE_LPI, &p->status) ) + return; + if ( p->desc != NULL ) clear_bit(_IRQ_INPROGRESS, &p->desc->status); clear_bit(GIC_IRQ_GUEST_VISIBLE, &p->status); diff --git a/xen/arch/arm/vgic-v3-its.c b/xen/arch/arm/vgic-v3-its.c index b7e61b2..0765810 100644 --- a/xen/arch/arm/vgic-v3-its.c +++ b/xen/arch/arm/vgic-v3-its.c @@ -618,6 +618,11 @@ static int its_handle_mapti(struct virt_its *its, uint64_t *cmdptr) goto out_remove_host_entry; pirq->lpi_vcpu_id = vcpu->vcpu_id; + /* + * Mark this LPI as new, so any older (now unmapped) LPI in any LR + * can be easily recognised as such. + */ + set_bit(GIC_IRQ_GUEST_PRISTINE_LPI, pirq->status); /* * Now insert the pending_irq into the domain's LPI tree, so that diff --git a/xen/include/asm-arm/vgic.h b/xen/include/asm-arm/vgic.h index 02732db..b1a7525 100644 --- a/xen/include/asm-arm/vgic.h +++ b/xen/include/asm-arm/vgic.h @@ -66,6 +66,7 @@ struct pending_irq #define GIC_IRQ_GUEST_VISIBLE 2 #define GIC_IRQ_GUEST_ENABLED 3 #define GIC_IRQ_GUEST_MIGRATING 4 +#define GIC_IRQ_GUEST_PRISTINE_LPI 5 unsigned long status; struct irq_desc *desc; /* only set it the irq corresponds to a physical irq */ unsigned int irq; -- 2.8.2 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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