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Similar to the host stage-2 CPU page table, the IOMMU pool is allocated early from the carveout and it's memory is added in a pool which the IOMMU driver can allocate from and reclaim at run time. As this is too early for drivers to use init calls, a default value can be set in the kernel config through IOMMU_POOL_PAGES, which then can be overridden later from the kernel command line: "kvm-arm.hyp_iommu_pages". Later when the driver registers, it will pass how many pages it needs, and if it was less than what was allocated, it will fail to register. Signed-off-by: Mostafa Saleh --- .../admin-guide/kernel-parameters.txt | 4 +++ arch/arm64/include/asm/kvm_host.h | 3 +- arch/arm64/kvm/Kconfig | 7 +++++ arch/arm64/kvm/hyp/include/nvhe/iommu.h | 5 ++- arch/arm64/kvm/hyp/nvhe/iommu/iommu.c | 20 +++++++++++- arch/arm64/kvm/hyp/nvhe/setup.c | 16 +++++++++- arch/arm64/kvm/iommu.c | 31 ++++++++++++++++++- arch/arm64/kvm/pkvm.c | 1 + 8 files changed, 82 insertions(+), 5 deletions(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 6c42061ca20e..f843d10a3dfc 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -3059,6 +3059,10 @@ trap: set WFI instruction trap notrap: clear WFI instruction trap + kvm-arm.hyp_iommu_pages= + [KVM, ARM, EARLY] + Number of pages allocated for the IOMMU pool from the + KVM carveout when running in protected mode. kvm_cma_resv_ratio=n [PPC,EARLY] Reserves given percentage from system memory area for diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index fb2551ba8798..5496c52d0163 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -1654,7 +1654,8 @@ static __always_inline enum fgt_group_id __fgt_reg_to_group_id(enum vcpu_sysreg #ifndef __KVM_NVHE_HYPERVISOR__ struct kvm_iommu_ops; -int kvm_iommu_register_driver(struct kvm_iommu_ops *hyp_ops); +int kvm_iommu_register_driver(struct kvm_iommu_ops *hyp_ops, size_t pool_pages); +size_t kvm_iommu_pages(void); #endif #endif /* __ARM64_KVM_HOST_H__ */ diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig index 4f803fd1c99a..6a1bd82a0d07 100644 --- a/arch/arm64/kvm/Kconfig +++ b/arch/arm64/kvm/Kconfig @@ -83,4 +83,11 @@ config PTDUMP_STAGE2_DEBUGFS If in doubt, say N. +config IOMMU_POOL_PAGES + hex "Number of pages reserved for IOMMU pool" + depends on KVM && IOMMU_SUPPORT + default 0x0 + help + IOMMU pool is used with protected mode to allocated IOMMU drivers page tables. + endif # VIRTUALIZATION diff --git a/arch/arm64/kvm/hyp/include/nvhe/iommu.h b/arch/arm64/kvm/hyp/include/nvhe/iommu.h index 219363045b1c..9f4906c6dcc9 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/iommu.h +++ b/arch/arm64/kvm/hyp/include/nvhe/iommu.h @@ -10,8 +10,11 @@ struct kvm_iommu_ops { void (*host_stage2_idmap)(phys_addr_t start, phys_addr_t end, int prot); }; -int kvm_iommu_init(void); +int kvm_iommu_init(void *pool_base, size_t nr_pages); void kvm_iommu_host_stage2_idmap(phys_addr_t start, phys_addr_t end, enum kvm_pgtable_prot prot); +void *kvm_iommu_donate_pages(u8 order); +void kvm_iommu_reclaim_pages(void *ptr); + #endif /* __ARM64_KVM_NVHE_IOMMU_H__ */ diff --git a/arch/arm64/kvm/hyp/nvhe/iommu/iommu.c b/arch/arm64/kvm/hyp/nvhe/iommu/iommu.c index 414bd4c97690..a0df34ecf6b0 100644 --- a/arch/arm64/kvm/hyp/nvhe/iommu/iommu.c +++ b/arch/arm64/kvm/hyp/nvhe/iommu/iommu.c @@ -15,6 +15,7 @@ struct kvm_iommu_ops *kvm_iommu_ops; /* Protected by host_mmu.lock */ static bool kvm_idmap_initialized; +static struct hyp_pool iommu_pages_pool; static inline int pkvm_to_iommu_prot(enum kvm_pgtable_prot prot) { @@ -72,7 +73,7 @@ static int kvm_iommu_snapshot_host_stage2(void) return ret; } -int kvm_iommu_init(void) +int kvm_iommu_init(void *pool_base, size_t nr_pages) { int ret; @@ -80,6 +81,13 @@ int kvm_iommu_init(void) !kvm_iommu_ops->host_stage2_idmap) return -ENODEV; + if (nr_pages) { + ret = hyp_pool_init(&iommu_pages_pool, hyp_virt_to_pfn(pool_base), + nr_pages, 0); + if (ret) + return ret; + } + ret = kvm_iommu_ops->init(); if (ret) return ret; @@ -95,3 +103,13 @@ void kvm_iommu_host_stage2_idmap(phys_addr_t start, phys_addr_t end, return; kvm_iommu_ops->host_stage2_idmap(start, end, pkvm_to_iommu_prot(prot)); } + +void *kvm_iommu_donate_pages(u8 order) +{ + return hyp_alloc_pages(&iommu_pages_pool, order); +} + +void kvm_iommu_reclaim_pages(void *ptr) +{ + hyp_put_page(&iommu_pages_pool, ptr); +} diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c index de79803e7439..c245ea88c480 100644 --- a/arch/arm64/kvm/hyp/nvhe/setup.c +++ b/arch/arm64/kvm/hyp/nvhe/setup.c @@ -22,6 +22,13 @@ unsigned long hyp_nr_cpus; +/* See kvm_iommu_pages() */ +#ifdef CONFIG_IOMMU_POOL_PAGES +size_t hyp_kvm_iommu_pages = CONFIG_IOMMU_POOL_PAGES; +#else +size_t hyp_kvm_iommu_pages; +#endif + #define hyp_percpu_size ((unsigned long)__per_cpu_end - \ (unsigned long)__per_cpu_start) @@ -33,6 +40,7 @@ static void *selftest_base; static void *ffa_proxy_pages; static struct kvm_pgtable_mm_ops pkvm_pgtable_mm_ops; static struct hyp_pool hpool; +static void *iommu_base; static int divide_memory_pool(void *virt, unsigned long size) { @@ -70,6 +78,12 @@ static int divide_memory_pool(void *virt, unsigned long size) if (!ffa_proxy_pages) return -ENOMEM; + if (hyp_kvm_iommu_pages) { + iommu_base = hyp_early_alloc_contig(hyp_kvm_iommu_pages); + if (!iommu_base) + return -ENOMEM; + } + return 0; } @@ -329,7 +343,7 @@ void __noreturn __pkvm_init_finalise(void) if (ret) goto out; - ret = kvm_iommu_init(); + ret = kvm_iommu_init(iommu_base, hyp_kvm_iommu_pages); if (ret) goto out; diff --git a/arch/arm64/kvm/iommu.c b/arch/arm64/kvm/iommu.c index c9041dcb6c57..6143fd3e1de3 100644 --- a/arch/arm64/kvm/iommu.c +++ b/arch/arm64/kvm/iommu.c @@ -7,9 +7,38 @@ #include extern struct kvm_iommu_ops *kvm_nvhe_sym(kvm_iommu_ops); +extern size_t kvm_nvhe_sym(hyp_kvm_iommu_pages); -int kvm_iommu_register_driver(struct kvm_iommu_ops *hyp_ops) +int kvm_iommu_register_driver(struct kvm_iommu_ops *hyp_ops, size_t pool_pages) { + /* See kvm_iommu_pages() */ + if (pool_pages > kvm_nvhe_sym(hyp_kvm_iommu_pages)) { + kvm_err("Missing memory for the IOMMU pool, need 0x%zx pages, check kvm-arm.hyp_iommu_pages", + pool_pages); + return -ENOMEM; + } + kvm_nvhe_sym(kvm_iommu_ops) = hyp_ops; return 0; } + +size_t kvm_iommu_pages(void) +{ + /* + * This is called very early during setup_arch() where no initcalls, + * so this has to call specific functions per each KVM driver. + * So we allow a config option that can set the defaul value for + * the IOMMU pool that can overridden by a command line option. + * When the driver registers it will pass the number pages needed + * for it's page tables, if less that what the system has already + * allocated we fail. + */ + return kvm_nvhe_sym(hyp_kvm_iommu_pages); +} + +/* Number of pages to reserve for iommu pool*/ +static int __init early_hyp_iommu_pages(char *arg) +{ + return kstrtoul(arg, 10, &kvm_nvhe_sym(hyp_kvm_iommu_pages)); +} +early_param("kvm-arm.hyp_iommu_pages", early_hyp_iommu_pages); diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c index 24f0f8a8c943..b9d212b48c04 100644 --- a/arch/arm64/kvm/pkvm.c +++ b/arch/arm64/kvm/pkvm.c @@ -63,6 +63,7 @@ void __init kvm_hyp_reserve(void) hyp_mem_pages += hyp_vmemmap_pages(STRUCT_HYP_PAGE_SIZE); hyp_mem_pages += pkvm_selftest_pages(); hyp_mem_pages += hyp_ffa_proxy_pages(); + hyp_mem_pages += kvm_iommu_pages(); /* * Try to allocate a PMD-aligned region to reduce TLB pressure once -- 2.52.0.rc1.455.g30608eb744-goog