On 26/02/20 21:10, Philippe Mathieu-Daudé wrote: > The vtd_find_as_from_bus_num() function was introduced (in commit > dbaabb25f) in a code format that could return an incorrect pointer, > which was later fixed by commit a2e1cd41ccf. > We could have avoid this by writing the if() statement differently. > Do it now, in case this function is re-used. The code is easier to > review (harder to miss bugs). > > Signed-off-by: Philippe Mathieu-Daudé <[email protected]> > --- > Since v2: Re-worded commit description, patch sent without -w. > > This patch is easier to review with 'git-diff -w' (--ignore-all-space): > > @@ -987,14 +987,17 @@ static bool vtd_slpte_nonzero_rsvd(uint64_t slpte, > uint32_t level) > static VTDBus *vtd_find_as_from_bus_num(IntelIOMMUState *s, uint8_t bus_num) > { > VTDBus *vtd_bus = s->vtd_as_by_bus_num[bus_num]; > - if (!vtd_bus) { > + GHashTableIter iter; > + > + if (vtd_bus) { > + return vtd_bus; > + } > + > /* > * Iterate over the registered buses to find the one which > * currently hold this bus number, and update the bus_num > * lookup table: > */ > - GHashTableIter iter; > - > g_hash_table_iter_init(&iter, s->vtd_as_by_busptr); > while (g_hash_table_iter_next(&iter, NULL, (void **)&vtd_bus)) { > if (pci_bus_num(vtd_bus->bus) == bus_num) { > @@ -1002,9 +1005,8 @@ static VTDBus *vtd_find_as_from_bus_num(IntelIOMMUState > *s, uint8_t bus_num) > return vtd_bus; > } > } > - vtd_bus = NULL; > - } > - return vtd_bus; > + > + return NULL; > } > --- > hw/i386/intel_iommu.c | 34 ++++++++++++++++++---------------- > 1 file changed, 18 insertions(+), 16 deletions(-) > > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c > index 6258c58ac9..e720a8939c 100644 > --- a/hw/i386/intel_iommu.c > +++ b/hw/i386/intel_iommu.c > @@ -987,24 +987,26 @@ static bool vtd_slpte_nonzero_rsvd(uint64_t slpte, > uint32_t level) > static VTDBus *vtd_find_as_from_bus_num(IntelIOMMUState *s, uint8_t bus_num) > { > VTDBus *vtd_bus = s->vtd_as_by_bus_num[bus_num]; > - if (!vtd_bus) { > - /* > - * Iterate over the registered buses to find the one which > - * currently hold this bus number, and update the bus_num > - * lookup table: > - */ > - GHashTableIter iter; > + GHashTableIter iter; > > - g_hash_table_iter_init(&iter, s->vtd_as_by_busptr); > - while (g_hash_table_iter_next(&iter, NULL, (void **)&vtd_bus)) { > - if (pci_bus_num(vtd_bus->bus) == bus_num) { > - s->vtd_as_by_bus_num[bus_num] = vtd_bus; > - return vtd_bus; > - } > - } > - vtd_bus = NULL; > + if (vtd_bus) { > + return vtd_bus; > } > - return vtd_bus; > + > + /* > + * Iterate over the registered buses to find the one which > + * currently hold this bus number, and update the bus_num > + * lookup table: > + */ > + g_hash_table_iter_init(&iter, s->vtd_as_by_busptr); > + while (g_hash_table_iter_next(&iter, NULL, (void **)&vtd_bus)) { > + if (pci_bus_num(vtd_bus->bus) == bus_num) { > + s->vtd_as_by_bus_num[bus_num] = vtd_bus; > + return vtd_bus; > + } > + } > + > + return NULL; > } > > /* Given the @iova, get relevant @slptep. @slpte_level will be the last level >
Queued, thanks. Paolo
