Re: [PATCH 2/2] hw/pci: Assert a bar is not registered multiple times

[Phil Dennis-Jordan]

Looks good to me. There is a risk here that the assertion will fail on existing code. (Unless you've rigorously audited all callers, which would be quite the task.) However, I agree that this would constitute a bug in the calling code, not an issue with this change. Since we've still got a few months left in the 10.0 release cycle, I say go for it - hopefully such bugs, if there are any, will be shaken out over the next few weeks.

On Fri, 17 Jan 2025 at 18:29, Nicholas Piggin <npiggin@gmail.com> wrote:

Nothing should be doing this, but it doesn't get caught by
pci_register_bar(). Add an assertion to prevent misuse.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>

Reviewed-by: Phil Dennis-Jordan <phil@philjordan.eu>

 

---
 hw/pci/pci.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/hw/pci/pci.c b/hw/pci/pci.c
index 2afa423925c..b067a55c5bc 100644
--- a/hw/pci/pci.c
+++ b/hw/pci/pci.c
@@ -1391,6 +1391,7 @@ void pci_register_bar(PCIDevice *pci_dev, int region_num,
     assert(hdr_type != PCI_HEADER_TYPE_BRIDGE || region_num < 2);

     r = &pci_dev->io_regions[region_num];
+    assert(!r->size);
     r->addr = PCI_BAR_UNMAPPED;
     r->size = size;
     r->type = type;
--
2.45.2