From 1b4277a04949dcfab4c24aa533ef17a0d878c19e Mon Sep 17 00:00:00 2001 From: Andrew Walbran Date: Tue, 19 Oct 2021 14:20:11 +0000 Subject: [PATCH] ANDROID: BACKPORT: 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. Signed-off-by: Andrew Walbran Bug: 171706629 [willdeacon@: Moved 'pkvm_ffa_id' to nvhe/mem_protect.h] Signed-off-by: Will Deacon Change-Id: Ib4d404cd1d4fa11d7bf8c1d0b8ec00838a8038a0 --- arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 5 +- arch/arm64/kvm/hyp/nvhe/mem_protect.c | 69 +++++++++++++++++++ 2 files changed, 73 insertions(+), 1 deletion(-) diff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h index 167a8577807d..0118a3b6b943 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h +++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h @@ -57,7 +57,8 @@ extern struct host_kvm host_kvm; typedef u32 pkvm_id; static const pkvm_id pkvm_host_id = 0; static const pkvm_id pkvm_hyp_id = (1 << 16); -static const pkvm_id pkvm_host_poison = pkvm_hyp_id + 1; +static const pkvm_id pkvm_ffa_id = pkvm_hyp_id + 1; /* Secure world */ +static const pkvm_id pkvm_host_poison = pkvm_ffa_id + 1; extern unsigned long hyp_nr_cpus; @@ -71,6 +72,8 @@ int __pkvm_host_share_guest(u64 pfn, u64 gfn, struct kvm_vcpu *vcpu); int __pkvm_host_donate_guest(u64 pfn, u64 gfn, struct kvm_vcpu *vcpu); int __pkvm_guest_share_host(struct kvm_vcpu *vcpu, u64 ipa); int __pkvm_guest_unshare_host(struct kvm_vcpu *vcpu, u64 ipa); +int __pkvm_host_share_ffa(u64 pfn, u64 nr_pages); +int __pkvm_host_unshare_ffa(u64 pfn, u64 nr_pages); int __pkvm_install_ioguard_page(struct kvm_vcpu *vcpu, u64 ipa); int __pkvm_remove_ioguard_page(struct kvm_vcpu *vcpu, u64 ipa); bool __pkvm_check_ioguard_page(struct kvm_vcpu *vcpu); diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c index 25b30cc98c55..aead9a12a971 100644 --- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c +++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c @@ -646,6 +646,7 @@ enum pkvm_component_id { PKVM_ID_HOST, PKVM_ID_HYP, PKVM_ID_GUEST, + PKVM_ID_FFA, }; struct pkvm_mem_transition { @@ -1222,6 +1223,13 @@ 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; } @@ -1259,6 +1267,13 @@ 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; } @@ -1313,6 +1328,10 @@ 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; } @@ -1347,6 +1366,10 @@ 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; } @@ -1778,6 +1801,52 @@ int __pkvm_host_donate_guest(u64 pfn, u64 gfn, struct kvm_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; +} + static int hyp_zero_page(phys_addr_t phys) { void *addr;