Re: [RFC PATCH v3 13/27] x86/sgx: Add helper to update SGX_LEPUBKEYHASHn MSRs
From: Jarkko Sakkinen <jarkko@kernel.org>
Date: 2021-01-30 16:23:19
On Tue, Jan 26, 2021 at 10:31:05PM +1300, Kai Huang wrote:
Add a helper to update SGX_LEPUBKEYHASHn MSRs. SGX virtualization also needs to update those MSRs based on guest's "virtual" SGX_LEPUBKEYHASHn before EINIT from guest. Signed-off-by: Kai Huang <redacted>
Acked-by: Jarkko Sakkinen <jarkko@kernel.org> /Jarkko
quoted hunk ↗ jump to hunk
--- v2->v3: - Added comment for sgx_update_lepubkeyhash(), per Jarkko and Dave. --- arch/x86/kernel/cpu/sgx/ioctl.c | 5 ++--- arch/x86/kernel/cpu/sgx/main.c | 15 +++++++++++++++ arch/x86/kernel/cpu/sgx/sgx.h | 2 ++ 3 files changed, 19 insertions(+), 3 deletions(-)diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioctl.c index e5977752c7be..1bae754268d1 100644 --- a/arch/x86/kernel/cpu/sgx/ioctl.c +++ b/arch/x86/kernel/cpu/sgx/ioctl.c@@ -495,7 +495,7 @@ static int sgx_encl_init(struct sgx_encl *encl, struct sgx_sigstruct *sigstruct, void *token) { u64 mrsigner[4]; - int i, j, k; + int i, j; void *addr; int ret;@@ -544,8 +544,7 @@ static int sgx_encl_init(struct sgx_encl *encl, struct sgx_sigstruct *sigstruct, preempt_disable(); - for (k = 0; k < 4; k++) - wrmsrl(MSR_IA32_SGXLEPUBKEYHASH0 + k, mrsigner[k]); + sgx_update_lepubkeyhash(mrsigner); ret = __einit(sigstruct, token, addr);diff --git a/arch/x86/kernel/cpu/sgx/main.c b/arch/x86/kernel/cpu/sgx/main.c index 93d249f7bff3..b456899a9532 100644 --- a/arch/x86/kernel/cpu/sgx/main.c +++ b/arch/x86/kernel/cpu/sgx/main.c@@ -697,6 +697,21 @@ static bool __init sgx_page_cache_init(void) return true; } + +/* + * Update the SGX_LEPUBKEYHASH MSRs to the values specified by caller. + * Bare-metal driver requires to update them to hash of enclave's signer + * before EINIT. KVM needs to update them to guest's virtual MSR values + * before doing EINIT from guest. + */ +void sgx_update_lepubkeyhash(u64 *lepubkeyhash) +{ + int i; + + for (i = 0; i < 4; i++) + wrmsrl(MSR_IA32_SGXLEPUBKEYHASH0 + i, lepubkeyhash[i]); +} + static int __init sgx_init(void) { int ret;diff --git a/arch/x86/kernel/cpu/sgx/sgx.h b/arch/x86/kernel/cpu/sgx/sgx.h index 509f2af33e1d..ccd4f145c464 100644 --- a/arch/x86/kernel/cpu/sgx/sgx.h +++ b/arch/x86/kernel/cpu/sgx/sgx.h@@ -83,4 +83,6 @@ void sgx_mark_page_reclaimable(struct sgx_epc_page *page); int sgx_unmark_page_reclaimable(struct sgx_epc_page *page); struct sgx_epc_page *sgx_alloc_epc_page(void *owner, bool reclaim); +void sgx_update_lepubkeyhash(u64 *lepubkeyhash); + #endif /* _X86_SGX_H */-- 2.29.2