diff options
authorCédric Le Goater <>2019-10-31 07:31:00 +0100
committerGreg Kroah-Hartman <>2019-12-17 20:39:41 +0100
commit9aeaa898f580ed9a20de0235430149a26da65d16 (patch)
parent6ff419d70d9f5bd65b3c59334acdc4e01466069b (diff)
powerpc/xive: Prevent page fault issues in the machine crash handler
commit 1ca3dec2b2dff9d286ce6cd64108bda0e98f9710 upstream. When the machine crash handler is invoked, all interrupts are masked but interrupts which have not been started yet do not have an ESB page mapped in the Linux address space. This crashes the 'crash kexec' sequence on sPAPR guests. To fix, force the mapping of the ESB page when an interrupt is being mapped in the Linux IRQ number space. This is done by setting the initial state of the interrupt to OFF which is not necessarily the case on PowerNV. Fixes: 243e25112d06 ("powerpc/xive: Native exploitation of the XIVE interrupt controller") Cc: # v4.12+ Signed-off-by: Cédric Le Goater <> Reviewed-by: Greg Kurz <> Signed-off-by: Michael Ellerman <> Link: Signed-off-by: Greg Kroah-Hartman <>
1 files changed, 9 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c
index 110d8bb16ebb..a820370883d9 100644
--- a/arch/powerpc/sysdev/xive/common.c
+++ b/arch/powerpc/sysdev/xive/common.c
@@ -967,6 +967,15 @@ static int xive_irq_alloc_data(unsigned int virq, irq_hw_number_t hw)
irq_set_handler_data(virq, xd);
+ /*
+ * Turn OFF by default the interrupt being mapped. A side
+ * effect of this check is the mapping the ESB page of the
+ * interrupt in the Linux address space. This prevents page
+ * fault issues in the crash handler which masks all
+ * interrupts.
+ */
+ xive_esb_read(xd, XIVE_ESB_SET_PQ_01);
return 0;