[PATCH] OvmfPkg: Report proper address space width for Cloud Hypervisor

[PATCH] OvmfPkg: Report proper address space width for Cloud Hypervisor

[Boeuf, Sebastien]

From: Sebastien Boeuf <sebastien.boeuf@intel.com>

The address space width isn't properly calculated when the platform is
Cloud Hypervisor. The function PlatformAddressWidthFromCpuid() must not
be invoked with the QemuQuirk boolean set to true in the Cloud
Hypervisor case.

Relying on the host bridge identifier, we can set the QemuQuirk to the
appropriate value, which results in the address space size to be
correctly returned for Cloud Hypervisor.

Having the correct address space width allows the code to calculate
dynamically the MMIO space available for devices in the 64-bit address
space, preventing it to fallback onto the default value (32GiB).

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
---
 OvmfPkg/Library/PlatformInitLib/MemDetect.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/OvmfPkg/Library/PlatformInitLib/MemDetect.c b/OvmfPkg/Library/PlatformInitLib/MemDetect.c
index 5aeeeff89f..a14e5c4247 100644
--- a/OvmfPkg/Library/PlatformInitLib/MemDetect.c
+++ b/OvmfPkg/Library/PlatformInitLib/MemDetect.c
@@ -838,6 +838,7 @@ PlatformAddressWidthInitialization (
 {
   UINT8       PhysMemAddressWidth;
   EFI_STATUS  Status;
+  BOOLEAN     QemuQuirk;
 
   if (PlatformInfoHob->HostBridgeDevId == 0xffff /* microvm */) {
     PlatformAddressWidthFromCpuid (PlatformInfoHob, FALSE);
@@ -863,7 +864,13 @@ PlatformAddressWidthInitialization (
     PlatformGetFirstNonAddress (PlatformInfoHob);
   }
 
-  PlatformAddressWidthFromCpuid (PlatformInfoHob, TRUE);
+  if (PlatformInfoHob->HostBridgeDevId == CLOUDHV_DEVICE_ID) {
+    QemuQuirk = FALSE;
+  } else {
+    QemuQuirk = TRUE;
+  }
+
+  PlatformAddressWidthFromCpuid (PlatformInfoHob, QemuQuirk);
   if (PlatformInfoHob->PhysMemAddressWidth != 0) {
     // physical address width is known
     PlatformDynamicMmioWindow (PlatformInfoHob);
-- 
2.37.2

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Re: [PATCH] OvmfPkg: Report proper address space width for Cloud Hypervisor

[Gerd Hoffmann]

On Wed, Jan 18, 2023 at 03:20:15PM +0100, sebastien.boeuf@intel.com wrote:
> From: Sebastien Boeuf <sebastien.boeuf@intel.com>
> 
> The address space width isn't properly calculated when the platform is
> Cloud Hypervisor. The function PlatformAddressWidthFromCpuid() must not
> be invoked with the QemuQuirk boolean set to true in the Cloud
> Hypervisor case.
> 
> Relying on the host bridge identifier, we can set the QemuQuirk to the
> appropriate value, which results in the address space size to be
> correctly returned for Cloud Hypervisor.
> 
> Having the correct address space width allows the code to calculate
> dynamically the MMIO space available for devices in the 64-bit address
> space, preventing it to fallback onto the default value (32GiB).
> 
> Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>

Acked-by: Gerd Hoffmann <kraxel@redhat.com>