From a6f65f4fc217713ee2c78b99baae1cc31c761778 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Date: Thu, 5 Mar 2020 11:27:02 +0100 Subject: hw/i386/intel_iommu: Simplify vtd_find_as_from_bus_num() logic MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 avoided 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). Reviewed-by: Peter Xu Reviewed-by: Eric Auger Signed-off-by: Philippe Mathieu-Daudé Message-Id: <20200305102702.31512-1-philmd@redhat.com> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/i386/intel_iommu.c | 32 +++++++++++++++++--------------- 1 file changed, 17 insertions(+), 15 deletions(-) (limited to 'hw') diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c index 6258c58..204b684 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; - } + if (vtd_bus) { + return vtd_bus; + } + + /* + * Iterate over the registered buses to find the one which + * currently holds 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; } - vtd_bus = NULL; } - return vtd_bus; + + return NULL; } /* Given the @iova, get relevant @slptep. @slpte_level will be the last level -- cgit v1.1