From: Brijesh Singh <brijesh.singh@amd.com>
To: <edk2-devel@lists.01.org>, <lersek@redhat.com>,
<jordan.l.justen@intel.com>
Cc: <Thomas.Lendacky@amd.com>, <leo.duran@amd.com>,
Brijesh Singh <brijesh.singh@amd.com>
Subject: [PATCH v5 14/14] OvmfPkg/QemuFwCfgLib: Add SEV support
Date: Mon, 22 May 2017 11:23:12 -0400 [thread overview]
Message-ID: <1495466592-21641-15-git-send-email-brijesh.singh@amd.com> (raw)
In-Reply-To: <1495466592-21641-1-git-send-email-brijesh.singh@amd.com>
When SEV is enabled, use a bounce buffer to perform the DMA operation.
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Brijesh Singh <brijesh.singh@amd.com>
---
OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c | 54 +++++++++++++++++++-
1 file changed, 52 insertions(+), 2 deletions(-)
diff --git a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c
index 73a19772bee1..40b43ac78ff4 100644
--- a/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c
+++ b/OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c
@@ -72,6 +72,8 @@ InternalQemuFwCfgDmaBytes (
volatile FW_CFG_DMA_ACCESS *Access;
UINT32 AccessHigh, AccessLow;
UINT32 Status;
+ UINT32 NumPages;
+ VOID *DmaBuffer, *BounceBuffer;
ASSERT (Control == FW_CFG_DMA_CTL_WRITE || Control == FW_CFG_DMA_CTL_READ ||
Control == FW_CFG_DMA_CTL_SKIP);
@@ -80,11 +82,44 @@ InternalQemuFwCfgDmaBytes (
return;
}
- Access = &LocalAccess;
+ //
+ // When SEV is enabled then allocate DMA bounce buffer
+ //
+ if (InternalQemuFwCfgSevIsEnabled ()) {
+ UINTN TotalSize;
+
+ TotalSize = sizeof (*Access);
+ //
+ // Control operation does not need buffer
+ //
+ if (Control != FW_CFG_DMA_CTL_SKIP) {
+ TotalSize += Size;
+ }
+
+ //
+ // Allocate SEV DMA buffer
+ //
+ NumPages = (UINT32)EFI_SIZE_TO_PAGES (TotalSize);
+ InternalQemuFwCfgSevDmaAllocateBuffer (&BounceBuffer, NumPages);
+
+ Access = BounceBuffer;
+ DmaBuffer = (UINT8*)BounceBuffer + sizeof (*Access);
+
+ //
+ // Decrypt data from encrypted guest buffer into DMA buffer
+ //
+ if (Control == FW_CFG_DMA_CTL_WRITE) {
+ CopyMem (DmaBuffer, Buffer, Size);
+ }
+ } else {
+ Access = &LocalAccess;
+ DmaBuffer = Buffer;
+ BounceBuffer = NULL;
+ }
Access->Control = SwapBytes32 (Control);
Access->Length = SwapBytes32 (Size);
- Access->Address = SwapBytes64 ((UINTN)Buffer);
+ Access->Address = SwapBytes64 ((UINTN)DmaBuffer);
//
// Delimit the transfer from (a) modifications to Access, (b) in case of a
@@ -117,6 +152,21 @@ InternalQemuFwCfgDmaBytes (
// After a read, the caller will want to use Buffer.
//
MemoryFence ();
+
+ //
+ // If Bounce buffer was allocated then copy the data into guest buffer and
+ // free the bounce buffer
+ //
+ if (BounceBuffer) {
+ //
+ // Encrypt the data from DMA buffer into guest buffer
+ //
+ if (Control == FW_CFG_DMA_CTL_READ) {
+ CopyMem (Buffer, DmaBuffer, Size);
+ }
+
+ InternalQemuFwCfgSevDmaFreeBuffer (BounceBuffer, NumPages);
+ }
}
--
2.7.4
next prev parent reply other threads:[~2017-05-22 15:23 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-22 15:22 [PATCH v5 00/14] x86: Secure Encrypted Virtualization (AMD) Brijesh Singh
2017-05-22 15:22 ` [PATCH v5 01/14] UefiCpuPkg: Define AMD Memory Encryption specific CPUID and MSR Brijesh Singh
2017-05-22 15:23 ` [PATCH v5 02/14] OvmfPkg/ResetVector: Set C-bit when building initial page table Brijesh Singh
2017-05-22 15:23 ` [PATCH v5 03/14] OvmfPkg: Update dsc to use IoLib from BaseIoLibIntrinsicSev.inf Brijesh Singh
2017-05-22 15:23 ` [PATCH v5 04/14] OvmfPkg/BaseMemcryptSevLib: Add SEV helper library Brijesh Singh
2017-05-24 13:06 ` Laszlo Ersek
2017-05-24 13:23 ` Brijesh Singh
2017-05-24 22:12 ` Brijesh Singh
2017-05-25 15:10 ` Laszlo Ersek
2017-05-25 18:23 ` Brijesh Singh
2017-05-22 15:23 ` [PATCH v5 05/14] OvmfPkg/PlatformPei: Set memory encryption PCD when SEV is enabled Brijesh Singh
2017-05-22 15:23 ` [PATCH v5 06/14] OvmfPkg:AmdSevDxe: Add AmdSevDxe driver Brijesh Singh
2017-05-24 14:17 ` Laszlo Ersek
2017-05-22 15:23 ` [PATCH v5 07/14] OvmfPkg:IoMmuDxe: Add IoMmuDxe driver Brijesh Singh
2017-05-24 15:09 ` Laszlo Ersek
2017-05-25 17:58 ` Laszlo Ersek
2017-05-25 18:56 ` Jordan Justen
2017-05-25 19:58 ` Laszlo Ersek
2017-05-22 15:23 ` [PATCH v5 08/14] OvmfPkg/QemuFwCfgLib: Provide Pei and Dxe specific library Brijesh Singh
2017-05-22 15:23 ` [PATCH v5 09/14] OvmfPkg/QemuFwCfgLib: Prepare for SEV support Brijesh Singh
2017-05-22 15:23 ` [PATCH v5 10/14] OvmfPkg/QemuFwCfgLib: Implement SEV internal function for SEC phase Brijesh Singh
2017-05-24 13:17 ` Laszlo Ersek
2017-05-22 15:23 ` [PATCH v5 11/14] OvmfPkg/QemuFwCfgLib: Implement SEV internal functions for PEI phase Brijesh Singh
2017-05-22 15:23 ` [PATCH v5 12/14] OvmfPkg/QemuFwCfgLib: Implement SEV internal function for Dxe phase Brijesh Singh
2017-05-24 13:45 ` Laszlo Ersek
2017-05-22 15:23 ` [PATCH v5 13/14] OvmfPkg/QemuFwCfgLib: Add option to dynamic alloc FW_CFG_DMA Access Brijesh Singh
2017-05-22 15:23 ` Brijesh Singh [this message]
2017-05-24 13:55 ` [PATCH v5 14/14] OvmfPkg/QemuFwCfgLib: Add SEV support Laszlo Ersek
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