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| author | Brijesh Singh <brijesh.singh@amd.com> | 2017-08-02 18:12:48 -0400 |
|---|---|---|
| committer | Laszlo Ersek <lersek@redhat.com> | 2017-08-05 02:54:33 +0200 |
| commit | f6c909ae5d659733b679ad0f77983dcc5d87d641 (patch) | |
| tree | e87b89b851de9b94bfb3595521dc5dfcec30d566 /BaseTools/Source/Python/sitecustomize.py | |
| parent | d0c9afea42a07c95613d0a33433ecefef824fcf3 (diff) | |
| download | edk2-f6c909ae5d659733b679ad0f77983dcc5d87d641.tar.gz edk2-f6c909ae5d659733b679ad0f77983dcc5d87d641.tar.bz2 edk2-f6c909ae5d659733b679ad0f77983dcc5d87d641.zip | |
OvmfPkg/QemuFwCfgLib: Use BusMasterCommonBuffer to map FW_CFG_DMA_ACCESS
Commit 09719a01b11b (OvmfPkg/QemuFwCfgLib: Implement SEV internal function
for Dxe phase) uses IOMMU protocol to allocate and free FW_CFG_DMA_ACCESS
buffer when SEV is active. During initial commits we made assumption that
IOMMU.AllocateBuffer() will provide PlainTextAddress (i.e C-bit cleared).
This assumption was wrong, the AllocateBuffer() protocol member is not
expected to produce a buffer that is immediatly usable, and client is
required to call Map() uncondtionally with BusMasterCommonBuffer[64] to
get a mapping which is accessable by both host and device.
The patch refactors code a bit and add the support to Map()
FW_CFG_DMA_ACCESS buffer using BusMasterCommonBuffer operation after
allocation and Unamp() before free.
The complete discussion about this and recommendation from Laszlo can be
found here [1]
[1] https://lists.01.org/pipermail/edk2-devel/2017-July/012652.html
Suggested-by: Laszlo Ersek <lersek@redhat.com>
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>
[lersek@redhat.com: convert pointers to UINTN before converting to UINT64]
[lersek@redhat.com: fix argument indentation in multi-line function call]
[lersek@redhat.com: explicitly compare pointers to NULL]
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Diffstat (limited to 'BaseTools/Source/Python/sitecustomize.py')
0 files changed, 0 insertions, 0 deletions