powerpc/xive: Add interrupt flag to disable automatic EOI

This will be used by KVM in order to keep escalation interrupts
in the non-EOI (masked) state after they fire. They will be
re-enabled directly in HW by KVM when needed.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

2 files changed, 5 insertions, 1 deletions

diff --git a/arch/powerpc/include/asm/xive.h b/arch/powerpc/include/asm/xive.h
index 0e77005cf021..b619a5585cd6 100644
--- a/arch/powerpc/include/asm/xive.h
+++ b/arch/powerpc/include/asm/xive.h
@@ -58,6 +58,9 @@ struct xive_irq_data {
 #define XIVE_IRQ_FLAG_EOI_FW    0x10
 #define XIVE_IRQ_FLAG_H_INT_ESB 0x20
 
+/* Special flag set by KVM for excalation interrupts */
+#define XIVE_IRQ_NO_EOI         0x80
+
 #define XIVE_INVALID_CHIP_ID    -1
 
 /* A queue tracking structure in a CPU */
diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c
index a3b8d7d1316e..2547b6021e6a 100644
--- a/arch/powerpc/sysdev/xive/common.c
+++ b/arch/powerpc/sysdev/xive/common.c
@@ -367,7 +367,8 @@ static void xive_irq_eoi(struct irq_data *d)
          * EOI the source if it hasn't been disabled and hasn't
          * been passed-through to a KVM guest
          */
-        if (!irqd_irq_disabled(d) && !irqd_is_forwarded_to_vcpu(d))
+        if (!irqd_irq_disabled(d) && !irqd_is_forwarded_to_vcpu(d) &&
+            !(xd->flags & XIVE_IRQ_NO_EOI))
                 xive_do_source_eoi(irqd_to_hwirq(d), xd);
 
         /*