diff options
| -rw-r--r-- | OvmfPkg/Library/PlatformInitLib/MemDetect.c | 41 | ||||
| -rw-r--r-- | OvmfPkg/PlatformPei/Platform.c | 2 |
2 files changed, 42 insertions, 1 deletions
diff --git a/OvmfPkg/Library/PlatformInitLib/MemDetect.c b/OvmfPkg/Library/PlatformInitLib/MemDetect.c index 83a7b67..c28d760 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 f006755..009db67 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);
|