From f7c4ae96ad34c040a1650626aa99ea7bec59ba92 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 29 Sep 2021 15:39:47 +0100 Subject: [PATCH] ANDROID: BACKPORT: arm64: Enroll into KVM's MMIO guard if required Should a guest desire to enroll into the MMIO guard, allow it to do so with a command-line option. Signed-off-by: Marc Zyngier Bug: 233587962 Change-Id: Ia9a77f693531740500739693c52b4959abacafd4 [willdeacon@: Add hypercall IDs] Signed-off-by: Will Deacon Signed-off-by: Quentin Perret --- .../admin-guide/kernel-parameters.txt | 3 + arch/arm64/Kconfig | 1 + arch/arm64/include/asm/hypervisor.h | 1 + arch/arm64/kernel/setup.c | 2 + arch/arm64/mm/ioremap.c | 58 +++++++++++++++++++ 5 files changed, 65 insertions(+) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index b25d51b36676..72874edc0320 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -2184,6 +2184,9 @@ 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 31cee7a9a8c9..9bf4dc17c574 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -28,6 +28,7 @@ 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 0aa634a1bf66..575eafcfcb66 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -50,6 +50,7 @@ #include #include #include +#include #include #include @@ -442,5 +443,6 @@ 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 89fbdff3afd0..8d0f8d7dbe53 100644 --- a/arch/arm64/mm/ioremap.c +++ b/arch/arm64/mm/ioremap.c @@ -11,6 +11,26 @@ #include #include +#ifndef ARM_SMCCC_KVM_FUNC_MMIO_GUARD_INFO +#define ARM_SMCCC_KVM_FUNC_MMIO_GUARD_INFO 5 + +#define ARM_SMCCC_VENDOR_HYP_KVM_MMIO_GUARD_INFO_FUNC_ID \ + ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ + ARM_SMCCC_SMC_64, \ + ARM_SMCCC_OWNER_VENDOR_HYP, \ + ARM_SMCCC_KVM_FUNC_MMIO_GUARD_INFO) +#endif /* ARM_SMCCC_KVM_FUNC_MMIO_GUARD_INFO */ + +#ifndef ARM_SMCCC_KVM_FUNC_MMIO_GUARD_ENROLL +#define ARM_SMCCC_KVM_FUNC_MMIO_GUARD_ENROLL 6 + +#define ARM_SMCCC_VENDOR_HYP_KVM_MMIO_GUARD_ENROLL_FUNC_ID \ + ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, \ + ARM_SMCCC_SMC_64, \ + ARM_SMCCC_OWNER_VENDOR_HYP, \ + ARM_SMCCC_KVM_FUNC_MMIO_GUARD_ENROLL) +#endif /* ARM_SMCCC_KVM_FUNC_MMIO_GUARD_ENROLL */ + #ifndef ARM_SMCCC_KVM_FUNC_MMIO_GUARD_MAP #define ARM_SMCCC_KVM_FUNC_MMIO_GUARD_MAP 7 @@ -39,6 +59,44 @@ 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))