After a reset of a QEMU -machine q35 guest, the PCI Express
Enhanced Configuration Mechanism is disabled and the variable
mmconfig no longer matches the configuration register PCIEXBAR
of the Q35 chipset. Until the variable mmconfig is reset to 0,
all pci_config_*() functions no longer work.
The variable mmconfig is located in the read-only F-segment.
To reset it the pci_config_*() functions are needed, but they
do not work.
Replace all pci_config_*() calls with Standard PCI Configuration
Mechanism pci_ioconfig_*() calls until mmconfig is reset to 0.
This fixes
In resume (status=0)
In 32bit resume
Attempting a hard reboot
Unable to unlock ram - bridge not found
and a reset loop with QEMU -accel tcg.
Reviewed-by: Gerd Hoffmann <kra...@redhat.com>
Signed-off-by: Volker Rümelin <vr_q...@t-online.de>
---
src/fw/shadow.c | 16 +++++++++-------
src/hw/pci.c | 32 ++++++++++++++++++++++++++++++++
src/hw/pci.h | 7 +++++++
3 files changed, 48 insertions(+), 7 deletions(-)
diff --git a/src/fw/shadow.c b/src/fw/shadow.c
index 4c627a8..0722df2 100644
--- a/src/fw/shadow.c
+++ b/src/fw/shadow.c
@@ -32,8 +32,8 @@ __make_bios_writable_intel(u16 bdf, u32 pam0)
{
// Read in current PAM settings from pci config space
union pamdata_u pamdata;
- pamdata.data32[0] = pci_config_readl(bdf, ALIGN_DOWN(pam0, 4));
- pamdata.data32[1] = pci_config_readl(bdf, ALIGN_DOWN(pam0, 4) + 4);
+ pamdata.data32[0] = pci_ioconfig_readl(bdf, ALIGN_DOWN(pam0, 4));
+ pamdata.data32[1] = pci_ioconfig_readl(bdf, ALIGN_DOWN(pam0, 4) + 4);
u8 *pam = &pamdata.data8[pam0 & 0x03];
// Make ram from 0xc0000-0xf0000 writable
@@ -46,8 +46,8 @@ __make_bios_writable_intel(u16 bdf, u32 pam0)
pam[0] = 0x30;
// Write PAM settings back to pci config space
- pci_config_writel(bdf, ALIGN_DOWN(pam0, 4), pamdata.data32[0]);
- pci_config_writel(bdf, ALIGN_DOWN(pam0, 4) + 4, pamdata.data32[1]);
+ pci_ioconfig_writel(bdf, ALIGN_DOWN(pam0, 4), pamdata.data32[0]);
+ pci_ioconfig_writel(bdf, ALIGN_DOWN(pam0, 4) + 4, pamdata.data32[1]);
if (!ram_present)
// Copy bios.
@@ -59,7 +59,7 @@ __make_bios_writable_intel(u16 bdf, u32 pam0)
static void
make_bios_writable_intel(u16 bdf, u32 pam0)
{
- int reg = pci_config_readb(bdf, pam0);
+ int reg = pci_ioconfig_readb(bdf, pam0);
if (!(reg & 0x10)) {
// QEMU doesn't fully implement the piix shadow capabilities -
// if ram isn't backing the bios segment when shadowing is
@@ -125,8 +125,8 @@ make_bios_writable(void)
// At this point, statically allocated variables can't be written,
// so do this search manually.
int bdf;
- foreachbdf(bdf, 0) {
- u32 vendev = pci_config_readl(bdf, PCI_VENDOR_ID);
+ pci_ioconfig_foreachbdf(bdf, 0) {
+ u32 vendev = pci_ioconfig_readl(bdf, PCI_VENDOR_ID);
u16 vendor = vendev & 0xffff, device = vendev >> 16;
if (vendor == PCI_VENDOR_ID_INTEL
&& device == PCI_DEVICE_ID_INTEL_82441) {
@@ -183,10 +183,12 @@ qemu_reboot(void)
apm_shutdown();
}
make_bios_writable();
+ pci_disable_mmconfig();
HaveRunPost = 3;
} else {
// Copy the BIOS making sure to only reset HaveRunPost at end
make_bios_writable();
+ pci_disable_mmconfig();
