diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 0d148f8a2635..43be9a642e85 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2082,6 +2082,9 @@ 1 - Bypass the IOMMU for DMA. unset - Use value of CONFIG_IOMMU_DEFAULT_PASSTHROUGH. + ioremap_guard [ARM64] enable the KVM MMIO guard functionality + if available. + io7= [HW] IO7 for Marvel-based Alpha systems See comment before marvel_specify_io7 in arch/alpha/kernel/core_marvel.c. diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 506531d8d0de..ea9042f795a0 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -25,6 +25,7 @@ config ARM64 select ARCH_HAS_FORTIFY_SOURCE select ARCH_HAS_GCOV_PROFILE_ALL select ARCH_HAS_GIGANTIC_PAGE + select ARCH_HAS_IOREMAP_PHYS_HOOKS select ARCH_HAS_KCOV select ARCH_HAS_KEEPINITRD select ARCH_HAS_MEMBARRIER_SYNC_CORE diff --git a/arch/arm64/include/asm/hypervisor.h b/arch/arm64/include/asm/hypervisor.h index ef8e55e6f2f2..ee45ae14be27 100644 --- a/arch/arm64/include/asm/hypervisor.h +++ b/arch/arm64/include/asm/hypervisor.h @@ -8,5 +8,6 @@ void kvm_init_hyp_services(void); bool kvm_arm_hyp_service_available(u32 func_id); void kvm_arm_init_hyp_services(void); void kvm_init_memshare_services(void); +void kvm_init_ioremap_services(void); #endif diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index fe86a244b350..6d5851bf913c 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -50,6 +50,7 @@ #include #include #include +#include #include #include @@ -449,5 +450,6 @@ device_initcall(register_arm64_panic_block); void kvm_arm_init_hyp_services(void) { + kvm_init_ioremap_services(); kvm_init_memshare_services(); } diff --git a/arch/arm64/mm/ioremap.c b/arch/arm64/mm/ioremap.c index 5334cbdc9f64..2ce207dd0cc7 100644 --- a/arch/arm64/mm/ioremap.c +++ b/arch/arm64/mm/ioremap.c @@ -30,6 +30,44 @@ static DEFINE_STATIC_KEY_FALSE(ioremap_guard_key); static DEFINE_XARRAY(ioremap_guard_array); static DEFINE_MUTEX(ioremap_guard_lock); +static bool ioremap_guard; +static int __init ioremap_guard_setup(char *str) +{ + ioremap_guard = true; + + return 0; +} +early_param("ioremap_guard", ioremap_guard_setup); + +void kvm_init_ioremap_services(void) +{ + struct arm_smccc_res res; + + if (!ioremap_guard) + return; + + /* We need all the functions to be implemented */ + if (!kvm_arm_hyp_service_available(ARM_SMCCC_KVM_FUNC_MMIO_GUARD_INFO) || + !kvm_arm_hyp_service_available(ARM_SMCCC_KVM_FUNC_MMIO_GUARD_ENROLL) || + !kvm_arm_hyp_service_available(ARM_SMCCC_KVM_FUNC_MMIO_GUARD_MAP) || + !kvm_arm_hyp_service_available(ARM_SMCCC_KVM_FUNC_MMIO_GUARD_UNMAP)) + return; + + arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_MMIO_GUARD_INFO_FUNC_ID, + 0, 0, 0, &res); + if (res.a0 != PAGE_SIZE) + return; + + arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_MMIO_GUARD_ENROLL_FUNC_ID, + &res); + if (res.a0 == SMCCC_RET_SUCCESS) { + static_branch_enable(&ioremap_guard_key); + pr_info("Using KVM MMIO guard for ioremap\n"); + } else { + pr_warn("KVM MMIO guard registration failed (%ld)\n", res.a0); + } +} + void ioremap_phys_range_hook(phys_addr_t phys_addr, size_t size, pgprot_t prot) { if (!static_branch_unlikely(&ioremap_guard_key))