Brijesh Singh f6c909ae5d OvmfPkg/QemuFwCfgLib: Use BusMasterCommonBuffer to map FW_CFG_DMA_ACCESS ... Commit 09719a01b1 (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>		2017-08-05 02:54:33 +02:00
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QemuFwCfgDxe.c	OvmfPkg/QemuFwCfgLib: Use BusMasterCommonBuffer to map FW_CFG_DMA_ACCESS	2017-08-05 02:54:33 +02:00
QemuFwCfgDxeLib.inf	OvmfPkg/QemuFwCfgLib: Implement SEV internal function for Dxe phase	2017-07-10 21:17:28 -07:00
QemuFwCfgLib.c	OvmfPkg/QemuFwCfgLib: Use BusMasterCommonBuffer to map FW_CFG_DMA_ACCESS	2017-08-05 02:54:33 +02:00
QemuFwCfgLibInternal.h	OvmfPkg/QemuFwCfgLib: Use BusMasterCommonBuffer to map FW_CFG_DMA_ACCESS	2017-08-05 02:54:33 +02:00
QemuFwCfgPei.c	OvmfPkg/QemuFwCfgLib: Use BusMasterCommonBuffer to map FW_CFG_DMA_ACCESS	2017-08-05 02:54:33 +02:00
QemuFwCfgPeiLib.inf	OvmfPkg/QemuFwCfgLib: Implement SEV internal functions for PEI phase	2017-07-10 21:17:28 -07:00
QemuFwCfgSec.c	OvmfPkg/QemuFwCfgLib: Use BusMasterCommonBuffer to map FW_CFG_DMA_ACCESS	2017-08-05 02:54:33 +02:00
QemuFwCfgSecLib.inf	OvmfPkg: Modify QemuFwCfgLib to use new IoLib class library	2017-01-17 10:11:41 +08:00