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Re: [PATCH v4 10/33] i386: Add get/set/migrate support for SGX_LEPUBKEYH
From: |
Philippe Mathieu-Daudé |
Subject: |
Re: [PATCH v4 10/33] i386: Add get/set/migrate support for SGX_LEPUBKEYHASH MSRs |
Date: |
Tue, 14 Sep 2021 08:38:59 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 |
On 7/19/21 1:21 PM, Yang Zhong wrote:
> From: Sean Christopherson <sean.j.christopherson@intel.com>
>
> On real hardware, on systems that supports SGX Launch Control, those
> MSRs are initialized to digest of Intel's signing key; on systems that
> don't support SGX Launch Control, those MSRs are not available but
> hardware always uses digest of Intel's signing key in EINIT.
>
> KVM advertises SGX LC via CPUID if and only if the MSRs are writable.
> Unconditionally initialize those MSRs to digest of Intel's signing key
> when CPU is realized and reset to reflect the fact. This avoids
> potential bug in case kvm_arch_put_registers() is called before
> kvm_arch_get_registers() is called, in which case guest's virtual
> SGX_LEPUBKEYHASH MSRs will be set to 0, although KVM initializes those
> to digest of Intel's signing key by default, since KVM allows those MSRs
> to be updated by Qemu to support live migration.
>
> Save/restore the SGX Launch Enclave Public Key Hash MSRs if SGX Launch
> Control (LC) is exposed to the guest. Likewise, migrate the MSRs if they
> are writable by the guest.
>
> Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
> Signed-off-by: Kai Huang <kai.huang@intel.com>
> Signed-off-by: Yang Zhong <yang.zhong@intel.com>
> ---
> target/i386/cpu.c | 17 ++++++++++++++++-
> target/i386/cpu.h | 1 +
> target/i386/kvm/kvm.c | 22 ++++++++++++++++++++++
> target/i386/machine.c | 20 ++++++++++++++++++++
> 4 files changed, 59 insertions(+), 1 deletion(-)
>
> diff --git a/target/i386/cpu.c b/target/i386/cpu.c
> index 840f825431..cea4307930 100644
> --- a/target/i386/cpu.c
> +++ b/target/i386/cpu.c
> @@ -5673,6 +5673,16 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index,
> uint32_t count,
> }
> }
>
> +#ifndef CONFIG_USER_ONLY
> +static void x86_cpu_set_sgxlepubkeyhash(CPUX86State *env)
> +{
> + env->msr_ia32_sgxlepubkeyhash[0] = 0xa6053e051270b7acULL;
> + env->msr_ia32_sgxlepubkeyhash[1] = 0x6cfbe8ba8b3b413dULL;
> + env->msr_ia32_sgxlepubkeyhash[2] = 0xc4916d99f2b3735dULL;
> + env->msr_ia32_sgxlepubkeyhash[3] = 0xd4f8c05909f9bb3bULL;
> +}
> +#endif
Maybe easier to move the #ifdef'ry inside the function.
Where these values come from btw?
> @@ -6186,6 +6198,10 @@ static void x86_cpu_realizefn(DeviceState *dev, Error
> **errp)
> & CPUID_EXT2_AMD_ALIASES);
> }
>
> +#ifndef CONFIG_USER_ONLY
> + x86_cpu_set_sgxlepubkeyhash(env);
> +#endif
> +
- Re: [PATCH v4 10/33] i386: Add get/set/migrate support for SGX_LEPUBKEYHASH MSRs,
Philippe Mathieu-Daudé <=