From ffa0e8607efbeb07dd3fb2319f4cfe81eadd1e3c Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Wed, 16 Nov 2022 17:03:31 +0000 Subject: [PATCH] BACKPORT: FROMLIST: KVM: arm64: Add FF-A helpers to share/unshare memory with secure world Extend pKVM's memory protection code so that we can update the host's stage-2 page-table to track pages shared with secure world by the host using FF-A and prevent those pages from being mapped into a guest. [ qperret: BACKPORT due to context conflicts in mem_protect.c caused by the presense of guest-related memory transition in the android kernel (host_donate_guest and friends) ] Bug: 254811097 Co-developed-by: Andrew Walbran Change-Id: Ib4d404cd1d4fa11d7bf8c1d0b8ec00838a8038a0 Signed-off-by: Andrew Walbran Signed-off-by: Will Deacon Signed-off-by: Quentin Perret Link: https://lore.kernel.org/r/20221116170335.2341003-9-qperret@google.com --- arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 3 + arch/arm64/kvm/hyp/nvhe/mem_protect.c | 69 +++++++++++++++++++ 2 files changed, 72 insertions(+) diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h index 7d0b49800bd8..abc366c4e8ad 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h +++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h @@ -58,6 +58,7 @@ enum pkvm_component_id { PKVM_ID_HOST, PKVM_ID_HYP, PKVM_ID_GUEST, + PKVM_ID_FFA, }; extern unsigned long hyp_nr_cpus; @@ -77,6 +78,8 @@ int __pkvm_guest_relinquish_to_host(struct pkvm_hyp_vcpu *vcpu, int __pkvm_install_ioguard_page(struct pkvm_hyp_vcpu *hyp_vcpu, u64 ipa); int __pkvm_remove_ioguard_page(struct pkvm_hyp_vcpu *hyp_vcpu, u64 ipa); bool __pkvm_check_ioguard_page(struct pkvm_hyp_vcpu *hyp_vcpu); +int __pkvm_host_share_ffa(u64 pfn, u64 nr_pages); +int __pkvm_host_unshare_ffa(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/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index cdf965814724..ab10ffb80558 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -1261,6 +1261,13 @@ static int check_share(struct pkvm_mem_share *share) case PKVM_ID_GUEST: ret = guest_ack_share(completer_addr, tx, share->completer_prot); break; + case PKVM_ID_FFA: + /* + * We only check the host; the secure side will check the other + * end when we forward the FFA call. + */ + ret = 0; + break; default: ret = -EINVAL; } @@ -1298,6 +1305,13 @@ static int __do_share(struct pkvm_mem_share *share) case PKVM_ID_GUEST: ret = guest_complete_share(completer_addr, tx, share->completer_prot); break; + case PKVM_ID_FFA: + /* + * We're not responsible for any secure page-tables, so there's + * nothing to do here. + */ + ret = 0; + break; default: ret = -EINVAL; } @@ -1352,6 +1366,10 @@ static int check_unshare(struct pkvm_mem_share *share) case PKVM_ID_HYP: ret = hyp_ack_unshare(completer_addr, tx); break; + case PKVM_ID_FFA: + /* See check_share() */ + ret = 0; + break; default: ret = -EINVAL; } @@ -1386,6 +1404,10 @@ static int __do_unshare(struct pkvm_mem_share *share) case PKVM_ID_HYP: ret = hyp_complete_unshare(completer_addr, tx); break; + case PKVM_ID_FFA: + /* See __do_share() */ + ret = 0; + break; default: ret = -EINVAL; } @@ -1821,6 +1843,53 @@ int __pkvm_host_donate_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu) return ret; } +int __pkvm_host_share_ffa(u64 pfn, u64 nr_pages) +{ + int ret; + struct pkvm_mem_share share = { + .tx = { + .nr_pages = nr_pages, + .initiator = { + .id = PKVM_ID_HOST, + .addr = hyp_pfn_to_phys(pfn), + }, + .completer = { + .id = PKVM_ID_FFA, + }, + }, + }; + + host_lock_component(); + ret = do_share(&share); + host_unlock_component(); + + return ret; +} + + +int __pkvm_host_unshare_ffa(u64 pfn, u64 nr_pages) +{ + int ret; + struct pkvm_mem_share share = { + .tx = { + .nr_pages = nr_pages, + .initiator = { + .id = PKVM_ID_HOST, + .addr = hyp_pfn_to_phys(pfn), + }, + .completer = { + .id = PKVM_ID_FFA, + }, + }, + }; + + host_lock_component(); + ret = do_unshare(&share); + host_unlock_component(); + + return ret; +} + void hyp_poison_page(phys_addr_t phys) { void *addr = hyp_fixmap_map(phys);