Hi Andre,
On 04/07/2017 06:32 PM, Andre Przywara wrote:
diff --git a/xen/arch/arm/gic-v3-lpi.c b/xen/arch/arm/gic-v3-lpi.c
index 292f2d0..5f3fe2c 100644
--- a/xen/arch/arm/gic-v3-lpi.c
+++ b/xen/arch/arm/gic-v3-lpi.c
@@ -136,6 +136,62 @@ uint64_t gicv3_get_redist_address(unsigned int cpu, bool
use_pta)
return per_cpu(lpi_redist, cpu).redist_id << 16;
}
+/*
+ * Handle incoming LPIs, which are a bit special, because they are potentially
+ * numerous and also only get injected into guests. Treat them specially here,
+ * by just looking up their target vCPU and virtual LPI number and hand it
+ * over to the injection function.
+ * Please note that LPIs are edge-triggered only, also have no active state,
+ * so spurious interrupts on the host side are no issue (we can just ignore
+ * them).
+ * Also a guest cannot expect that firing interrupts that haven't been
+ * fully configured yet will reach the CPU, so we don't need to care about
+ * this special case.
+ */
+void gicv3_do_LPI(unsigned int lpi)
+{
+ struct domain *d;
+ union host_lpi *hlpip, hlpi;
+ struct vcpu *vcpu;
As mentioned on the last 2 previous version, you will need irq_enter and
irq_exit in the return path. So the common code know you are in an
interrupt handler (see in_irq()).
+
+ /* EOI the LPI already. */
+ WRITE_SYSREG32(lpi, ICC_EOIR1_EL1);
+
+ /* Find out if a guest mapped something to this physical LPI. */
+ hlpip = gic_get_host_lpi(lpi);
+ if ( !hlpip )
+ return;
+
+ hlpi.data = read_u64_atomic(&hlpip->data);
+
+ /*
+ * Unmapped events are marked with an invalid LPI ID. We can safely
+ * ignore them, as they have no further state and no-one can expect
+ * to see them if they have not been mapped.
+ */
+ if ( hlpi.virt_lpi == INVALID_LPI )
+ return;
+
+ d = rcu_lock_domain_by_id(hlpi.dom_id);
+ if ( !d )
+ return;
+
+ /* Make sure we don't step beyond the vcpu array. */
+ if ( hlpi.vcpu_id >= d->max_vcpus )
+ {
+ rcu_unlock_domain(d);
+ return;
+ }
+
+ vcpu = d->vcpu[hlpi.vcpu_id];
+
+ /* Check if the VCPU is ready to receive LPIs. */
+ if ( vcpu->arch.vgic.flags & VGIC_V3_LPIS_ENABLED )
+ vgic_vcpu_inject_irq(vcpu, hlpi.virt_lpi);
+
+ rcu_unlock_domain(d);
+}
+
static int gicv3_lpi_allocate_pendtable(uint64_t *reg)
{
uint64_t val;
Cheers,
--
Julien Grall
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