From: Prasad J Pandit <p...@fedoraproject.org> Add spapr msi mmio read method to avoid NULL pointer dereference issue.
Reported-by: Lei Sun <slei.cas...@gmail.com> Acked-by: David Gibson <da...@gibson.dropbear.id.au> Reviewed-by: Li Qiang <liq...@gmail.com> Signed-off-by: Prasad J Pandit <p...@fedoraproject.org> --- hw/ppc/spapr_pci.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) Update v4: fix multi-line comment and log guest_error -> https://lists.nongnu.org/archive/html/qemu-devel/2020-07/msg05311.html diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c index 363cdb3f7b..53dfd3d8c6 100644 --- a/hw/ppc/spapr_pci.c +++ b/hw/ppc/spapr_pci.c @@ -52,6 +52,7 @@ #include "sysemu/kvm.h" #include "sysemu/hostmem.h" #include "sysemu/numa.h" +#include "qemu/log.h" /* Copied from the kernel arch/powerpc/platforms/pseries/msi.c */ #define RTAS_QUERY_FN 0 @@ -738,6 +739,12 @@ static PCIINTxRoute spapr_route_intx_pin_to_irq(void *opaque, int pin) return route; } +static uint64_t spapr_msi_read(void *opaque, hwaddr addr, unsigned size) +{ + qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid access\n", __func__); + return 0; +} + /* * MSI/MSIX memory region implementation. * The handler handles both MSI and MSIX. @@ -755,8 +762,11 @@ static void spapr_msi_write(void *opaque, hwaddr addr, } static const MemoryRegionOps spapr_msi_ops = { - /* There is no .read as the read result is undefined by PCI spec */ - .read = NULL, + /* + * .read result is undefined by PCI spec. + * define .read method to avoid assert failure in memory_region_init_io + */ + .read = spapr_msi_read, .write = spapr_msi_write, .endianness = DEVICE_LITTLE_ENDIAN }; -- 2.26.2
