| Message ID | 1348606761-44739-1-git-send-email-mjr@cs.wisc.edu |
|---|---|
| State | New |
| Headers | show |
On Tue, 2012-09-25 at 15:59 -0500, mjr@cs.wisc.edu wrote: > From: Matt Renzelmann <mjr@cs.wisc.edu> > > The current implementation of pci_find_space does not properly align > PCI capabilities in the PCI configuration space. This patch fixes > this issue. > > Signed-off-by: Matt Renzelmann <mjr@cs.wisc.edu> > --- > > This is my first patch to QEMU so I hope I'm not screwing up too much. > The purpose of this patch is to mask off the low-order two bits--Linux > masks these while scanning the PCI configuration space, for example, > so we need to make sure QEMU's behavior matches the standard. > > No current QEMU hardware is likely using this but it may be important > later. > > hw/pci.c | 14 ++++++++++---- > 1 files changed, 10 insertions(+), 4 deletions(-) > > diff --git a/hw/pci.c b/hw/pci.c > index e149305..8771b7e 100644 > --- a/hw/pci.c > +++ b/hw/pci.c > @@ -1571,11 +1571,17 @@ static int pci_find_space(PCIDevice *pdev, uint8_t size) > int config_size = pci_config_size(pdev); > int offset = PCI_CONFIG_HEADER_SIZE; > int i; > - for (i = PCI_CONFIG_HEADER_SIZE; i < config_size; ++i) > - if (pdev->used[i]) > - offset = i + 1; > - else if (i - offset + 1 == size) > + int masked; > + > + for (i = PCI_CONFIG_HEADER_SIZE; i < config_size; ++i) { > + masked = i & (~3); > + if (pdev->used[i]) { > + offset = masked + 4; > + } else if (i - offset + 1 == size) { > return offset; > + } > + } > + > return 0; > } > I think you could just search every 4th byte. In fact, this whole used byte-map could be turned into a single uint64_t bitmap for standard config space. Thanks, Alex
diff --git a/hw/pci.c b/hw/pci.c index e149305..8771b7e 100644 --- a/hw/pci.c +++ b/hw/pci.c @@ -1571,11 +1571,17 @@ static int pci_find_space(PCIDevice *pdev, uint8_t size) int config_size = pci_config_size(pdev); int offset = PCI_CONFIG_HEADER_SIZE; int i; - for (i = PCI_CONFIG_HEADER_SIZE; i < config_size; ++i) - if (pdev->used[i]) - offset = i + 1; - else if (i - offset + 1 == size) + int masked; + + for (i = PCI_CONFIG_HEADER_SIZE; i < config_size; ++i) { + masked = i & (~3); + if (pdev->used[i]) { + offset = masked + 4; + } else if (i - offset + 1 == size) { return offset; + } + } + return 0; }