edk2.git - Cross-platform firmware development environment

	Commit message (Collapse)	Author	Age	Files	Lines
*	OvmfPkg/QemuFlashFvbServicesRuntimeDxe: Bypass flash detection with SEV-ES	Tom Lendacky	2020-08-17	1	-0/+16
\| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \|	BZ: https://bugzilla.tianocore.org/show_bug.cgi?id=2198 The flash detection routine will attempt to determine how the flash device behaves (e.g. ROM, RAM, Flash). But when SEV-ES is enabled and the flash device behaves as a ROM device (meaning it is marked read-only by the hypervisor), this check may result in an infinite nested page fault because of the attempted write. Since the instruction cannot be emulated when SEV-ES is enabled, the RIP is never advanced, resulting in repeated nested page faults. When SEV-ES is enabled, exit the flash detection early and assume that the FD behaves as Flash. This will result in QemuFlashWrite() being called to store EFI variables, which will also result in an infinite nested page fault when the write is performed. In this case, update QemuFlashWrite() to use the VMGEXIT MMIO write support to have the hypervisor perform the write without having to emulate the instruction. Cc: Jordan Justen <jordan.l.justen@intel.com> Cc: Laszlo Ersek <lersek@redhat.com> Cc: Ard Biesheuvel <ard.biesheuvel@arm.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com> Regression-tested-by: Laszlo Ersek <lersek@redhat.com>
*	OvmfPkg: Replace BSD License with BSD+Patent License	Michael D Kinney	2019-04-09	1	-7/+1
\| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \| \|	https://bugzilla.tianocore.org/show_bug.cgi?id=1373 Replace BSD 2-Clause License with BSD+Patent License. This change is based on the following emails: https://lists.01.org/pipermail/edk2-devel/2019-February/036260.html https://lists.01.org/pipermail/edk2-devel/2018-October/030385.html RFCs with detailed process for the license change: V3: https://lists.01.org/pipermail/edk2-devel/2019-March/038116.html V2: https://lists.01.org/pipermail/edk2-devel/2019-March/037669.html V1: https://lists.01.org/pipermail/edk2-devel/2019-March/037500.html Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com>
*	OvmfPkg/QemuFlashFvbServicesRuntimeDxe: Clear C-bit when SEV is active	Brijesh Singh	2018-03-09	1	-0/+54
	Commit:24e4ad7 (OvmfPkg: Add AmdSevDxe driver) added a driver which runs early in DXE phase and clears the C-bit from NonExistent entry -- which is later split and accommodate the flash MMIO. When SMM is enabled, we build two sets of page tables; first page table is used when executing code in non SMM mode (SMM-less-pgtable) and second page table is used when we are executing code in SMM mode (SMM-pgtable). During boot time, AmdSevDxe driver clears the C-bit from the SMM-less-pgtable. But when SMM is enabled, Qemu Flash services are used from SMM mode. In this patch we explicitly clear the C-bit from Qemu flash MMIO range before we probe the flash. When OVMF is built with SMM_REQUIRE then call to initialize the flash services happen after the SMM-pgtable is created and processor has served the first SMI. At this time we will have access to the SMM-pgtable. Cc: Jordan Justen <jordan.l.justen@intel.com> Cc: Laszlo Ersek <lersek@redhat.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Brijesh Singh <brijesh.singh@amd.com> [lersek@redhat.com: trivial coding style improvements] Reviewed-by: Laszlo Ersek <lersek@redhat.com>