OvmfPkg/VirtioRngDxe: check if device is ready

Add a 'Ready' boolean to the driver state struct, use it to track
whenever the device is ready to be used.  In case it is not ready
throw an EFI_DEVICE_ERROR instead of sending a request which will
never receive an answer.

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

2 files changed, 11 insertions, 3 deletions

diff --git a/OvmfPkg/VirtioRngDxe/VirtioRng.c b/OvmfPkg/VirtioRngDxe/VirtioRng.c
index 069aed1..8959e51 100644
--- a/OvmfPkg/VirtioRngDxe/VirtioRng.c
+++ b/OvmfPkg/VirtioRngDxe/VirtioRng.c
@@ -156,6 +156,11 @@ VirtioRngGetRNG (
   }

 

   Dev = VIRTIO_ENTROPY_SOURCE_FROM_RNG (This);

+  if (!Dev->Ready) {

+    DEBUG ((DEBUG_INFO, "%a: not ready\n", __func__));

+    return EFI_DEVICE_ERROR;

+  }

+

   //

   // Map Buffer's system physical address to device address

   //

@@ -382,6 +387,7 @@ VirtioRngInit (
   //

   Dev->Rng.GetInfo = VirtioRngGetInfo;

   Dev->Rng.GetRNG  = VirtioRngGetRNG;

+  Dev->Ready       = TRUE;

 

   return EFI_SUCCESS;

 

@@ -414,8 +420,8 @@ VirtioRngUninit (
   // VIRTIO_CFG_WRITE() returns, the host will have learned to stay away from

   // the old comms area.

   //

+  Dev->Ready = FALSE;

   Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, 0);

-

   Dev->VirtIo->UnmapSharedBuffer (Dev->VirtIo, Dev->RingMap);

 

   VirtioRingUninit (Dev->VirtIo, &Dev->Ring);

@@ -435,7 +441,7 @@ VirtioRngExitBoot (
 {

   VIRTIO_RNG_DEV  *Dev;

 

-  DEBUG ((DEBUG_VERBOSE, "%a: Context=0x%p\n", __func__, Context));

+  DEBUG ((DEBUG_INFO, "%a: Context=0x%p\n", __func__, Context));

   //

   // Reset the device. This causes the hypervisor to forget about the virtio

   // ring.

@@ -443,7 +449,8 @@ VirtioRngExitBoot (
   // We allocated said ring in EfiBootServicesData type memory, and code

   // executing after ExitBootServices() is permitted to overwrite it.

   //

-  Dev = Context;

+  Dev        = Context;

+  Dev->Ready = FALSE;

   Dev->VirtIo->SetDeviceStatus (Dev->VirtIo, 0);

 }

 

diff --git a/OvmfPkg/VirtioRngDxe/VirtioRng.h b/OvmfPkg/VirtioRngDxe/VirtioRng.h
index 2da9954..3519521 100644
--- a/OvmfPkg/VirtioRngDxe/VirtioRng.h
+++ b/OvmfPkg/VirtioRngDxe/VirtioRng.h
@@ -33,6 +33,7 @@ typedef struct {
   VRING                     Ring;           // VirtioRingInit       2

   EFI_RNG_PROTOCOL          Rng;            // VirtioRngInit        1

   VOID                      *RingMap;       // VirtioRingMap        2

+  BOOLEAN                   Ready;

 } VIRTIO_RNG_DEV;

 

 #define VIRTIO_ENTROPY_SOURCE_FROM_RNG(RngPointer) \