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authorGerd Hoffmann <kraxel@redhat.com>2022-06-02 10:42:15 +0200
committermergify[bot] <37929162+mergify[bot]@users.noreply.github.com>2022-06-03 09:06:44 +0000
commitbd10d4e20143ec776c748cc1f5ffcd3812492800 (patch)
tree53570086d5e7f9c66fefac613eef4be16067ef53
parentad3bafa7d5ec61848e9a86929ba7a7c7cbcc8eff (diff)
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OvmfPkg/Microvm/pcie: mPhysMemAddressWidth tweak
microvm places the 64bit mmio space at the end of the physical address space. So mPhysMemAddressWidth must be correct, otherwise the pci host bridge setup throws an error because it thinks the 64bit mmio window is not addressable. On microvm we can simply use standard cpuid to figure the address width because the host-phys-bits option (-cpu ${name},host-phys-bits=on) is forced to be enabled. Side note: For 'pc' and 'q35' this is not the case for backward compatibility reasons. Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
-rw-r--r--OvmfPkg/Library/PlatformInitLib/MemDetect.c41
-rw-r--r--OvmfPkg/PlatformPei/Platform.c2
2 files changed, 42 insertions, 1 deletions
diff --git a/OvmfPkg/Library/PlatformInitLib/MemDetect.c b/OvmfPkg/Library/PlatformInitLib/MemDetect.c
index 83a7b6726b..c28d7601f8 100644
--- a/OvmfPkg/Library/PlatformInitLib/MemDetect.c
+++ b/OvmfPkg/Library/PlatformInitLib/MemDetect.c
@@ -491,6 +491,42 @@ PlatformGetFirstNonAddress (
return FirstNonAddress;
}
+/*
+ * Use CPUID to figure physical address width. Does *not* work
+ * reliable on qemu. For historical reasons qemu returns phys-bits=40
+ * even in case the host machine supports less than that.
+ *
+ * qemu has a cpu property (host-phys-bits={on,off}) to change that
+ * and make sure guest phys-bits are not larger than host phys-bits.,
+ * but it is off by default. Exception: microvm machine type
+ * hard-wires that property to on.
+ */
+VOID
+EFIAPI
+PlatformAddressWidthFromCpuid (
+ IN OUT EFI_HOB_PLATFORM_INFO *PlatformInfoHob
+ )
+{
+ UINT32 RegEax;
+
+ AsmCpuid (0x80000000, &RegEax, NULL, NULL, NULL);
+ if (RegEax >= 0x80000008) {
+ AsmCpuid (0x80000008, &RegEax, NULL, NULL, NULL);
+ PlatformInfoHob->PhysMemAddressWidth = (UINT8)RegEax;
+ } else {
+ PlatformInfoHob->PhysMemAddressWidth = 36;
+ }
+
+ PlatformInfoHob->FirstNonAddress = LShiftU64 (1, PlatformInfoHob->PhysMemAddressWidth);
+
+ DEBUG ((
+ DEBUG_INFO,
+ "%a: cpuid: phys-bits is %d\n",
+ __FUNCTION__,
+ PlatformInfoHob->PhysMemAddressWidth
+ ));
+}
+
/**
Initialize the PhysMemAddressWidth field in PlatformInfoHob based on guest RAM size.
**/
@@ -503,6 +539,11 @@ PlatformAddressWidthInitialization (
UINT64 FirstNonAddress;
UINT8 PhysMemAddressWidth;
+ if (PlatformInfoHob->HostBridgeDevId == 0xffff /* microvm */) {
+ PlatformAddressWidthFromCpuid (PlatformInfoHob);
+ return;
+ }
+
//
// As guest-physical memory size grows, the permanent PEI RAM requirements
// are dominated by the identity-mapping page tables built by the DXE IPL.
diff --git a/OvmfPkg/PlatformPei/Platform.c b/OvmfPkg/PlatformPei/Platform.c
index f006755d5f..009db67ee6 100644
--- a/OvmfPkg/PlatformPei/Platform.c
+++ b/OvmfPkg/PlatformPei/Platform.c
@@ -357,12 +357,12 @@ InitializePlatform (
S3Verification ();
BootModeInitialization (&mPlatformInfoHob);
- AddressWidthInitialization (&mPlatformInfoHob);
//
// Query Host Bridge DID
//
mPlatformInfoHob.HostBridgeDevId = PciRead16 (OVMF_HOSTBRIDGE_DID);
+ AddressWidthInitialization (&mPlatformInfoHob);
MaxCpuCountInitialization (&mPlatformInfoHob);