The recently reworked do_share() infrastructure for the nVHE protected mode allows to transition the state of a range of pages 'atomically'. This is preferable over single-page sharing when e.g. mapping guest vCPUs in the hypervisor stage-1 as the permission checks and page-table modifications for the entire range are done in a single critical section. This means there is no need for the host the handle e.g. only half of a vCPU being successfully shared with the hypervisor.
So, make use of that feature in the __pkvm_host_share_hyp() hypercall by allowing to specify a pfn range. Signed-off-by: Quentin Perret <[email protected]> --- arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 2 +- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 3 ++- arch/arm64/kvm/hyp/nvhe/mem_protect.c | 4 +-- arch/arm64/kvm/mmu.c | 25 +++++++------------ 4 files changed, 14 insertions(+), 20 deletions(-) diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h index 56445586c755..9c02abe92e0a 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h +++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h @@ -54,7 +54,7 @@ extern struct host_kvm host_kvm; extern const u8 pkvm_hyp_id; int __pkvm_prot_finalize(void); -int __pkvm_host_share_hyp(u64 pfn); +int __pkvm_host_share_hyp(u64 pfn, u64 nr_pages); bool addr_is_memory(phys_addr_t phys); int host_stage2_idmap_locked(phys_addr_t addr, u64 size, enum kvm_pgtable_prot prot); diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 2da6aa8da868..f78bec2b9dd4 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -143,8 +143,9 @@ static void handle___pkvm_cpu_set_vector(struct kvm_cpu_context *host_ctxt) static void handle___pkvm_host_share_hyp(struct kvm_cpu_context *host_ctxt) { DECLARE_REG(u64, pfn, host_ctxt, 1); + DECLARE_REG(u64, nr_pages, host_ctxt, 2); - cpu_reg(host_ctxt, 1) = __pkvm_host_share_hyp(pfn); + cpu_reg(host_ctxt, 1) = __pkvm_host_share_hyp(pfn, nr_pages); } static void handle___pkvm_create_private_mapping(struct kvm_cpu_context *host_ctxt) diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index 6983b83f799f..909e60f71b06 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -671,14 +671,14 @@ static int do_share(struct pkvm_mem_share *share) return ret; } -int __pkvm_host_share_hyp(u64 pfn) +int __pkvm_host_share_hyp(u64 pfn, u64 nr_pages) { int ret; u64 host_addr = hyp_pfn_to_phys(pfn); u64 hyp_addr = (u64)__hyp_va(host_addr); struct pkvm_mem_share share = { .tx = { - .nr_pages = 1, + .nr_pages = nr_pages, .initiator = { .id = PKVM_ID_HOST, .addr = host_addr, diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c index f80673e863ac..bc9865a8c988 100644 --- a/arch/arm64/kvm/mmu.c +++ b/arch/arm64/kvm/mmu.c @@ -281,30 +281,23 @@ static phys_addr_t kvm_kaddr_to_phys(void *kaddr) } } -static int pkvm_share_hyp(phys_addr_t start, phys_addr_t end) -{ - phys_addr_t addr; - int ret; - - for (addr = ALIGN_DOWN(start, PAGE_SIZE); addr < end; addr += PAGE_SIZE) { - ret = kvm_call_hyp_nvhe(__pkvm_host_share_hyp, - __phys_to_pfn(addr)); - if (ret) - return ret; - } - - return 0; -} - int kvm_share_hyp(void *from, void *to) { + phys_addr_t start, end; + u64 nr_pages; + if (is_kernel_in_hyp_mode()) return 0; if (kvm_host_owns_hyp_mappings()) return create_hyp_mappings(from, to, PAGE_HYP); - return pkvm_share_hyp(kvm_kaddr_to_phys(from), kvm_kaddr_to_phys(to)); + start = ALIGN_DOWN(kvm_kaddr_to_phys(from), PAGE_SIZE); + end = PAGE_ALIGN(kvm_kaddr_to_phys(to)); + nr_pages = (end - start) >> PAGE_SHIFT; + + return kvm_call_hyp_nvhe(__pkvm_host_share_hyp, __phys_to_pfn(start), + nr_pages); } /** -- 2.33.0.882.g93a45727a2-goog _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
