Hi Philippe, On 2/25/21 11:08 AM, Philippe Mathieu-Daudé wrote: > On 2/25/21 10:14 AM, Eric Auger wrote: >> With -Werror=maybe-uninitialized configuration we get >> ../hw/i386/intel_iommu.c: In function ‘vtd_context_device_invalidate’: >> ../hw/i386/intel_iommu.c:1888:10: error: ‘mask’ may be used >> uninitialized in this function [-Werror=maybe-uninitialized] >> 1888 | mask = ~mask; >> | ~~~~~^~~~~~~ >> >> Add a g_assert_not_reached() to avoid the error. >> >> Signed-off-by: Eric Auger <eric.au...@redhat.com> >> --- >> hw/i386/intel_iommu.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c >> index b4f5094259..3206f379f8 100644 >> --- a/hw/i386/intel_iommu.c >> +++ b/hw/i386/intel_iommu.c >> @@ -1884,6 +1884,8 @@ static void >> vtd_context_device_invalidate(IntelIOMMUState *s, >> case 3: >> mask = 7; /* Mask bit 2:0 in the SID field */ >> break; >> + default: >> + g_assert_not_reached(); >> } >> mask = ~mask; > > Unrelated to this patch, but I wonder why we don't directly assign the > correct value of the mask in the switch cases...
After reading the vtd spec again, I think this is aligned with the spec description. FM = function mask encodes the bits to mask. Then you actually compute the mask by ~mask. > > Reviewed-by: Philippe Mathieu-Daudé <phi...@redhat.com> Thanks! Eric > > set the mask > diuse the >> >> >
