commit 8347b99473a313be6549a5b940bc3c56a71be81c upstream.
Copy the incoming @data comman to an internal buffer so that callers can
put SEV command buffers on the stack without running afoul of
CONFIG_VMAP_STACK=y, i.e. without bombing on vmalloc'd pointers. As of
today, the largest supported command takes a 68 byte buffer, i.e. pretty
much every command can be put on the stack. Because sev_cmd_mutex is
held for the entirety of a transaction, only a single bounce buffer is
required.
Use the internal buffer unconditionally, as the majority of in-kernel
users will soon switch to using the stack. At that point, checking
virt_addr_valid() becomes (negligible) overhead in most cases, and
supporting both paths slightly increases complexity. Since the commands
are all quite small, the cost of the copies is insignificant compared to
the latency of communicating with the PSP.
Allocate a full page for the buffer as opportunistic preparation for
SEV-SNP, which requires the command buffer to be in firmware state for
commands that trigger memory writes from the PSP firmware. Using a full
page now will allow SEV-SNP support to simply transition the page as
needed.
Cc: Brijesh Singh <brijesh.singh@amd.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210406224952.4177376-5-seanjc@google.com>
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Ben Hutchings <benh@debian.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 38103671aad38e888743dd26c767869cfc15adca ]
Drop the dedicated status_cmd_buf and instead use a local variable for
PLATFORM_STATUS. Now that the low level helper uses an internal buffer
for all commands, using the stack for the upper layers is safe even when
running with CONFIG_VMAP_STACK=y.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210406224952.4177376-7-seanjc@google.com>
Reviewed-by: Brijesh Singh <brijesh.singh@amd.com>
Acked-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Stable-dep-of: 91dfd98216d8 ("crypto: ccp - Avoid page allocation failure warning for SEV_GET_ID2")
Signed-off-by: Sasha Levin <sashal@kernel.org>
The PSP (Platform Security Processor) provides support for key management
commands in Secure Encrypted Virtualization (SEV) mode, along with
software-based Trusted Execution Environment (TEE) to enable third-party
Trusted Applications.
Therefore, introduce psp-dev.c and psp-dev.h files, which can invoke
SEV (or TEE) initialization based on platform feature support.
TEE interface support will be introduced in a later patch.
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Jens Wiklander <jens.wiklander@linaro.org>
Co-developed-by: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
Signed-off-by: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
Signed-off-by: Rijo Thomas <Rijo-john.Thomas@amd.com>
Acked-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
