diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 8bb2c7422cc8..34c9950884d5 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -4,6 +4,7 @@ * Author: Christoffer Dall */ +#include #include #include #include @@ -2638,6 +2639,22 @@ static int init_pkvm_host_sve_state(void) return 0; } +static int pkvm_check_sme_dvmsync_fw_call(void) +{ + struct arm_smccc_res res; + + if (!cpus_have_final_cap(ARM64_WORKAROUND_4193714)) + return 0; + + arm_smccc_1_1_smc(ARM_SMCCC_CPU_WORKAROUND_4193714, &res); + if (res.a0) { + kvm_err("pKVM requires firmware support for C1-Pro erratum 4193714\n"); + return -ENODEV; + } + + return 0; +} + /* * Finalizes the initialization of hyp mode, once everything else is initialized * and the initialziation process cannot fail. @@ -2838,6 +2855,10 @@ static int __init init_hyp_mode(void) if (err) goto out_err; + err = pkvm_check_sme_dvmsync_fw_call(); + if (err) + goto out_err; + err = kvm_hyp_init_protection(hyp_va_bits); if (err) { kvm_err("Failed to init hyp memory protection\n"); diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index 28a471d1927c..a3050e2b65b1 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -5,6 +5,7 @@ */ #include + #include #include #include @@ -14,6 +15,7 @@ #include +#include #include #include #include @@ -29,6 +31,19 @@ static struct hyp_pool host_s2_pool; static DEFINE_PER_CPU(struct pkvm_hyp_vm *, __current_vm); #define current_vm (*this_cpu_ptr(&__current_vm)) +static void pkvm_sme_dvmsync_fw_call(void) +{ + if (alternative_has_cap_unlikely(ARM64_WORKAROUND_4193714)) { + struct arm_smccc_res res; + + /* + * Ignore the return value. Probing for the workaround + * availability took place in init_hyp_mode(). + */ + hyp_smccc_1_1_smc(ARM_SMCCC_CPU_WORKAROUND_4193714, &res); + } +} + static void guest_lock_component(struct pkvm_hyp_vm *vm) { hyp_spin_lock(&vm->lock); @@ -574,8 +589,14 @@ static int host_stage2_set_owner_metadata_locked(phys_addr_t addr, u64 size, ret = host_stage2_try(kvm_pgtable_stage2_annotate, &host_mmu.pgt, addr, size, &host_s2_pool, KVM_HOST_INVALID_PTE_TYPE_DONATION, annotation); - if (!ret) + if (!ret) { + /* + * After stage2 maintenance has happened, but before the page + * owner has changed. + */ + pkvm_sme_dvmsync_fw_call(); __host_update_page_state(addr, size, PKVM_NOPAGE); + } return ret; } diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h index 50b47eba7d01..e7195750d21b 100644 --- a/include/linux/arm-smccc.h +++ b/include/linux/arm-smccc.h @@ -105,6 +105,12 @@ ARM_SMCCC_SMC_32, \ 0, 0x3fff) +/* C1-Pro erratum 4193714: SME DVMSync early acknowledgement */ +#define ARM_SMCCC_CPU_WORKAROUND_4193714 \ + ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ + ARM_SMCCC_SMC_32, \ + ARM_SMCCC_OWNER_CPU, 0x10) + #define ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID \ ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ ARM_SMCCC_SMC_32, \