4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
commit 9728a7c8ab2f7a1c8d5c95278d2e4f4ac1285385 upstream.
The icp-opal call is missing the code from icp-native to recover
interrupts snatched by KVM. Without that, when running KVM, we can
get into a situation where an interrupt is lost and the CPU stuck
with an elevated CPPR.
Also harden replay by always checking the return from opal_int_eoi().
Fixes: d74361881f0d ("powerpc/xics: Add ICP OPAL backend")
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/powerpc/sysdev/xics/icp-opal.c | 31 ++++++++++++++++++++++++-------
1 file changed, 24 insertions(+), 7 deletions(-)
--- a/arch/powerpc/sysdev/xics/icp-opal.c
+++ b/arch/powerpc/sysdev/xics/icp-opal.c
@@ -20,6 +20,7 @@
#include <asm/xics.h>
#include <asm/io.h>
#include <asm/opal.h>
+#include <asm/kvm_ppc.h>
static void icp_opal_teardown_cpu(void)
{
@@ -39,7 +40,26 @@ static void icp_opal_flush_ipi(void)
* Should we be flagging idle loop instead?
* Or creating some task to be scheduled?
*/
- opal_int_eoi((0x00 << 24) | XICS_IPI);
+ if (opal_int_eoi((0x00 << 24) | XICS_IPI) > 0)
+ force_external_irq_replay();
+}
+
+static unsigned int icp_opal_get_xirr(void)
+{
+ unsigned int kvm_xirr;
+ __be32 hw_xirr;
+ int64_t rc;
+
+ /* Handle an interrupt latched by KVM first */
+ kvm_xirr = kvmppc_get_xics_latch();
+ if (kvm_xirr)
+ return kvm_xirr;
+
+ /* Then ask OPAL */
+ rc = opal_int_get_xirr(&hw_xirr, false);
+ if (rc < 0)
+ return 0;
+ return be32_to_cpu(hw_xirr);
}
static unsigned int icp_opal_get_irq(void)
@@ -47,12 +67,8 @@ static unsigned int icp_opal_get_irq(voi
unsigned int xirr;
unsigned int vec;
unsigned int irq;
- int64_t rc;
- rc = opal_int_get_xirr(&xirr, false);
- if (rc < 0)
- return 0;
- xirr = be32_to_cpu(xirr);
+ xirr = icp_opal_get_xirr();
vec = xirr & 0x00ffffff;
if (vec == XICS_IRQ_SPURIOUS)
return 0;
@@ -67,7 +83,8 @@ static unsigned int icp_opal_get_irq(voi
xics_mask_unknown_vec(vec);
/* We might learn about it later, so EOI it */
- opal_int_eoi(xirr);
+ if (opal_int_eoi(xirr) > 0)
+ force_external_irq_replay();
return 0;
}
--
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