On Mon, Jun 20, 2022 at 4:02 PM Ashish Kalra <Ashish.Kalra@xxxxxxx> wrote: > > From: Brijesh Singh <brijesh.singh@xxxxxxx> > > SEV-SNP FW >= 1.51 requires that SYSCFG.MFMD must be set. > > Subsequent CCP patches while require 1.51 as the minimum SEV-SNP > firmware version. > > Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx> > --- > arch/x86/include/asm/msr-index.h | 3 +++ > arch/x86/kernel/sev.c | 24 ++++++++++++++++++++++++ > 2 files changed, 27 insertions(+) > > diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h > index 57a8280e283a..1e36f16daa56 100644 > --- a/arch/x86/include/asm/msr-index.h > +++ b/arch/x86/include/asm/msr-index.h > @@ -587,6 +587,9 @@ > #define MSR_AMD64_SYSCFG_SNP_EN BIT_ULL(MSR_AMD64_SYSCFG_SNP_EN_BIT) > #define MSR_AMD64_SYSCFG_SNP_VMPL_EN_BIT 25 > #define MSR_AMD64_SYSCFG_SNP_VMPL_EN BIT_ULL(MSR_AMD64_SYSCFG_SNP_VMPL_EN_BIT) > +#define MSR_AMD64_SYSCFG_MFDM_BIT 19 > +#define MSR_AMD64_SYSCFG_MFDM BIT_ULL(MSR_AMD64_SYSCFG_MFDM_BIT) nit: Similar to the previous patch, the alignment here doesn't look right. The bad alignment can be viewed on the github version of this patch: https://github.com/AMDESE/linux/commit/6d4469b86f90e67119ff110230857788a0d9dbd0 > + > #define MSR_K8_INT_PENDING_MSG 0xc0010055 > /* C1E active bits in int pending message */ > #define K8_INTP_C1E_ACTIVE_MASK 0x18000000 > diff --git a/arch/x86/kernel/sev.c b/arch/x86/kernel/sev.c > index 3a233b5d47c5..25c7feb367f6 100644 > --- a/arch/x86/kernel/sev.c > +++ b/arch/x86/kernel/sev.c > @@ -2257,6 +2257,27 @@ static __init void snp_enable(void *arg) > __snp_enable(smp_processor_id()); > } > > +static int __mfdm_enable(unsigned int cpu) > +{ > + u64 val; > + > + if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) > + return 0; > + > + rdmsrl(MSR_AMD64_SYSCFG, val); > + > + val |= MSR_AMD64_SYSCFG_MFDM; Can we do this inside `__snp_enable()`, above? Then, we'll execute if a hotplug event happens as well. static int __snp_enable(unsigned int cpu) { u64 val; if (!cpu_feature_enabled(X86_FEATURE_SEV_SNP)) return 0; rdmsrl(MSR_AMD64_SYSCFG, val); val |= MSR_AMD64_SYSCFG_SNP_EN; val |= MSR_AMD64_SYSCFG_SNP_VMPL_EN; val |= MSR_AMD64_SYSCFG_MFDM; wrmsrl(MSR_AMD64_SYSCFG, val); return 0; } > + > + wrmsrl(MSR_AMD64_SYSCFG, val); > + > + return 0; > +} > + > +static __init void mfdm_enable(void *arg) > +{ > + __mfdm_enable(smp_processor_id()); > +} > + > static bool get_rmptable_info(u64 *start, u64 *len) > { > u64 calc_rmp_sz, rmp_sz, rmp_base, rmp_end, nr_pages; > @@ -2325,6 +2346,9 @@ static __init int __snp_rmptable_init(void) > /* Flush the caches to ensure that data is written before SNP is enabled. */ > wbinvd_on_all_cpus(); > > + /* MFDM must be enabled on all the CPUs prior to enabling SNP. */ > + on_each_cpu(mfdm_enable, NULL, 1); > + > /* Enable SNP on all CPUs. */ > on_each_cpu(snp_enable, NULL, 1); > > -- > 2.25.1 >
