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Re: [Qemu-devel] [RE-RESEND PATCH] pci: Adjust PCI config limit based on
From: |
Alex Williamson |
Subject: |
Re: [Qemu-devel] [RE-RESEND PATCH] pci: Adjust PCI config limit based on bus topology |
Date: |
Wed, 17 Feb 2016 13:28:12 -0700 |
Hi Michael,
Would you like me to send this for a 4th time or are you OK with me
pulling this through my tree with Marcel's R-b? Thanks,
Alex
On Mon, 18 Jan 2016 16:06:03 -0700
Alex Williamson <address@hidden> wrote:
> A conventional PCI bus does not support config space accesses above
> the standard 256 byte configuration space. PCIe-to-PCI bridges are
> not permitted to forward transactions if the extended register address
> field is non-zero and must handle it as an unsupported request (PCIe
> bridge spec rev 1.0, 4.1.3, 4.1.4). Therefore, we should not support
> extended config space if there is a conventional bus anywhere on the
> path to a device.
>
> Signed-off-by: Alex Williamson <address@hidden>
> ---
> Previous postings:
> https://lists.gnu.org/archive/html/qemu-devel/2015-10/msg05384.html
> https://lists.gnu.org/archive/html/qemu-devel/2015-11/msg02422.html
>
> hw/pci/pci_host.c | 26 ++++++++++++++++++++++++++
> 1 file changed, 26 insertions(+)
>
> diff --git a/hw/pci/pci_host.c b/hw/pci/pci_host.c
> index 49f59a5..3a3e294 100644
> --- a/hw/pci/pci_host.c
> +++ b/hw/pci/pci_host.c
> @@ -19,6 +19,7 @@
> */
>
> #include "hw/pci/pci.h"
> +#include "hw/pci/pci_bridge.h"
> #include "hw/pci/pci_host.h"
> #include "hw/pci/pci_bus.h"
> #include "trace.h"
> @@ -49,9 +50,29 @@ static inline PCIDevice *pci_dev_find_by_addr(PCIBus *bus,
> uint32_t addr)
> return pci_find_device(bus, bus_num, devfn);
> }
>
> +static void pci_adjust_config_limit(PCIBus *bus, uint32_t *limit)
> +{
> + if (*limit > PCI_CONFIG_SPACE_SIZE) {
> + if (!pci_bus_is_express(bus)) {
> + *limit = PCI_CONFIG_SPACE_SIZE;
> + return;
> + }
> +
> + if (!pci_bus_is_root(bus)) {
> + PCIDevice *bridge = pci_bridge_get_device(bus);
> + pci_adjust_config_limit(bridge->bus, limit);
> + }
> + }
> +}
> +
> void pci_host_config_write_common(PCIDevice *pci_dev, uint32_t addr,
> uint32_t limit, uint32_t val, uint32_t len)
> {
> + pci_adjust_config_limit(pci_dev->bus, &limit);
> + if (limit <= addr) {
> + return;
> + }
> +
> assert(len <= 4);
> /* non-zero functions are only exposed when function 0 is present,
> * allowing direct removal of unexposed functions.
> @@ -70,6 +91,11 @@ uint32_t pci_host_config_read_common(PCIDevice *pci_dev,
> uint32_t addr,
> {
> uint32_t ret;
>
> + pci_adjust_config_limit(pci_dev->bus, &limit);
> + if (limit <= addr) {
> + return ~0x0;
> + }
> +
> assert(len <= 4);
> /* non-zero functions are only exposed when function 0 is present,
> * allowing direct removal of unexposed functions.
>
- Re: [Qemu-devel] [RE-RESEND PATCH] pci: Adjust PCI config limit based on bus topology,
Alex Williamson <=