ANDROID: KVM: arm64: Drop pkvm_mem_transition for host-to-guest donations
Simplify the __pkvm_host_donate_guest() path by not using the
pkvm_mem_transition machinery. As this removes the last user of the
do_donate() helper and pkvm_mem_transition struct, remove all the
related code.
No functional changes intended
Change-Id: Ifc5ffcff41814b3f1f33c44c51ba46d8e97256d0
Signed-off-by: Quentin Perret <qperret@google.com>
diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index 0ab1a91..2fb1627 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -850,42 +850,6 @@ void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt)
trace_host_mem_abort(esr, addr);
}
-struct pkvm_mem_transition {
- u64 nr_pages;
-
- struct {
- enum pkvm_component_id id;
- /* Address in the initiator's address space */
- u64 addr;
-
- union {
- struct {
- /* Address in the completer's address space */
- u64 completer_addr;
- } host;
- struct {
- u64 completer_addr;
- } hyp;
- struct {
- struct pkvm_hyp_vcpu *hyp_vcpu;
- } guest;
- };
- } initiator;
-
- struct {
- enum pkvm_component_id id;
-
- union {
- struct {
- struct pkvm_hyp_vcpu *hyp_vcpu;
- phys_addr_t phys;
- } guest;
- };
-
- const enum kvm_pgtable_prot prot;
- } completer;
-};
-
struct check_walk_data {
enum pkvm_page_state desired;
enum pkvm_page_state (*get_page_state)(kvm_pte_t pte, u64 addr);
@@ -993,56 +957,6 @@ static int __host_set_page_state_range(u64 addr, u64 size,
return 0;
}
-static int host_request_owned_transition(u64 *completer_addr,
- const struct pkvm_mem_transition *tx)
-{
- u64 size = tx->nr_pages * PAGE_SIZE;
- u64 addr = tx->initiator.addr;
-
- *completer_addr = tx->initiator.host.completer_addr;
- return __host_check_page_state_range(addr, size, PKVM_PAGE_OWNED);
-}
-
-static int host_initiate_donation(u64 *completer_addr,
- const struct pkvm_mem_transition *tx)
-{
- u8 owner_id = tx->completer.id;
- u64 size = tx->nr_pages * PAGE_SIZE;
-
- *completer_addr = tx->initiator.host.completer_addr;
- return host_stage2_set_owner_locked(tx->initiator.addr, size, owner_id);
-}
-
-static bool __host_ack_skip_pgtable_check(const struct pkvm_mem_transition *tx)
-{
- return !(IS_ENABLED(CONFIG_NVHE_EL2_DEBUG) ||
- tx->initiator.id != PKVM_ID_HYP);
-}
-
-static int __host_ack_transition(u64 addr, const struct pkvm_mem_transition *tx,
- enum pkvm_page_state state)
-{
- u64 size = tx->nr_pages * PAGE_SIZE;
-
- if (__host_ack_skip_pgtable_check(tx))
- return 0;
-
- return __host_check_page_state_range(addr, size, state);
-}
-
-static int host_ack_donation(u64 addr, const struct pkvm_mem_transition *tx)
-{
- return __host_ack_transition(addr, tx, PKVM_NOPAGE);
-}
-
-static int host_complete_donation(u64 addr, const struct pkvm_mem_transition *tx)
-{
- u64 size = tx->nr_pages * PAGE_SIZE;
- u8 host_id = tx->completer.id;
-
- return host_stage2_set_owner_locked(addr, size, host_id);
-}
-
static enum pkvm_page_state hyp_get_page_state(kvm_pte_t pte, u64 addr)
{
enum pkvm_page_state state = 0;
@@ -1070,53 +984,6 @@ static int __hyp_check_page_state_range(u64 addr, u64 size,
return check_page_state_range(&pkvm_pgtable, addr, size, &d);
}
-static int hyp_request_donation(u64 *completer_addr,
- const struct pkvm_mem_transition *tx)
-{
- u64 size = tx->nr_pages * PAGE_SIZE;
- u64 addr = tx->initiator.addr;
-
- *completer_addr = tx->initiator.hyp.completer_addr;
- return __hyp_check_page_state_range(addr, size, PKVM_PAGE_OWNED);
-}
-
-static int hyp_initiate_donation(u64 *completer_addr,
- const struct pkvm_mem_transition *tx)
-{
- u64 size = tx->nr_pages * PAGE_SIZE;
- int ret;
-
- *completer_addr = tx->initiator.hyp.completer_addr;
- ret = kvm_pgtable_hyp_unmap(&pkvm_pgtable, tx->initiator.addr, size);
- return (ret != size) ? -EFAULT : 0;
-}
-
-static bool __hyp_ack_skip_pgtable_check(const struct pkvm_mem_transition *tx)
-{
- return !(IS_ENABLED(CONFIG_NVHE_EL2_DEBUG) ||
- tx->initiator.id != PKVM_ID_HOST);
-}
-
-static int hyp_ack_donation(u64 addr, const struct pkvm_mem_transition *tx)
-{
- u64 size = tx->nr_pages * PAGE_SIZE;
-
- if (__hyp_ack_skip_pgtable_check(tx))
- return 0;
-
- return __hyp_check_page_state_range(addr, size, PKVM_NOPAGE);
-}
-
-static int hyp_complete_donation(u64 addr,
- const struct pkvm_mem_transition *tx)
-{
- void *start = (void *)addr, *end = start + (tx->nr_pages * PAGE_SIZE);
- enum kvm_pgtable_prot prot = tx->completer.prot;
-
- prot = pkvm_mkstate(prot, PKVM_PAGE_OWNED);
- return pkvm_create_mappings_locked(start, end, prot);
-}
-
static enum pkvm_page_state guest_get_page_state(kvm_pte_t pte, u64 addr)
{
enum pkvm_page_state state = 0;
@@ -1145,54 +1012,6 @@ static int __guest_check_page_state_range(struct pkvm_hyp_vcpu *vcpu, u64 addr,
return check_page_state_range(&vm->pgt, addr, size, &d);
}
-static int guest_ack_donation(u64 addr, const struct pkvm_mem_transition *tx)
-{
- u64 size = tx->nr_pages * PAGE_SIZE;
-
- if (!addr_is_memory(tx->completer.guest.phys))
- return -EPERM;
-
- return __guest_check_page_state_range(tx->completer.guest.hyp_vcpu,
- addr, size, PKVM_NOPAGE);
-}
-
-static int guest_complete_donation(u64 addr, const struct pkvm_mem_transition *tx)
-{
- enum kvm_pgtable_prot prot = pkvm_mkstate(KVM_PGTABLE_PROT_RWX, PKVM_PAGE_OWNED);
- struct pkvm_hyp_vcpu *vcpu = tx->completer.guest.hyp_vcpu;
- struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu);
- phys_addr_t phys = tx->completer.guest.phys;
- u64 size = tx->nr_pages * PAGE_SIZE;
- int err;
-
- if (tx->initiator.id == PKVM_ID_HOST)
- psci_mem_protect_inc(tx->nr_pages);
-
- if (pkvm_ipa_range_has_pvmfw(vm, addr, addr + size)) {
- if (WARN_ON(!pkvm_hyp_vcpu_is_protected(vcpu))) {
- err = -EPERM;
- goto err_undo_psci;
- }
-
- WARN_ON(tx->initiator.id != PKVM_ID_HOST);
- err = pkvm_load_pvmfw_pages(vm, addr, phys, size);
- if (err)
- goto err_undo_psci;
- }
-
- /*
- * If this fails, we effectively leak the pages since they're now
- * owned by the guest but not mapped into its stage-2 page-table.
- */
- return kvm_pgtable_stage2_map(&vm->pgt, addr, size, phys, prot,
- &vcpu->vcpu.arch.stage2_mc, 0);
-
-err_undo_psci:
- if (tx->initiator.id == PKVM_ID_HOST)
- psci_mem_protect_dec(tx->nr_pages);
- return err;
-}
-
static int __guest_request_page_transition(u64 ipa, u64 *__phys, u64 nr_pages,
struct pkvm_hyp_vcpu *vcpu,
enum pkvm_page_state desired)
@@ -1261,98 +1080,6 @@ static int __guest_initiate_page_transition(u64 ipa, u64 *__phys, u64 nr_pages,
return 0;
}
-static int check_donation(struct pkvm_mem_transition *tx)
-{
- u64 completer_addr;
- int ret;
-
- switch (tx->initiator.id) {
- case PKVM_ID_HOST:
- ret = host_request_owned_transition(&completer_addr, tx);
- break;
- case PKVM_ID_HYP:
- ret = hyp_request_donation(&completer_addr, tx);
- break;
- default:
- ret = -EINVAL;
- }
-
- if (ret)
- return ret;
-
- switch (tx->completer.id) {
- case PKVM_ID_HOST:
- ret = host_ack_donation(completer_addr, tx);
- break;
- case PKVM_ID_HYP:
- ret = hyp_ack_donation(completer_addr, tx);
- break;
- case PKVM_ID_GUEST:
- ret = guest_ack_donation(completer_addr, tx);
- break;
- default:
- ret = -EINVAL;
- }
-
- return ret;
-}
-
-static int __do_donate(struct pkvm_mem_transition *tx)
-{
- u64 completer_addr;
- int ret;
-
- switch (tx->initiator.id) {
- case PKVM_ID_HOST:
- ret = host_initiate_donation(&completer_addr, tx);
- break;
- case PKVM_ID_HYP:
- ret = hyp_initiate_donation(&completer_addr, tx);
- break;
- default:
- ret = -EINVAL;
- }
-
- if (ret)
- return ret;
-
- switch (tx->completer.id) {
- case PKVM_ID_HOST:
- ret = host_complete_donation(completer_addr, tx);
- break;
- case PKVM_ID_HYP:
- ret = hyp_complete_donation(completer_addr, tx);
- break;
- case PKVM_ID_GUEST:
- ret = guest_complete_donation(completer_addr, tx);
- break;
- default:
- ret = -EINVAL;
- }
-
- return ret;
-}
-
-/*
- * do_donate():
- *
- * The page owner transfers ownership to another component, losing access
- * as a consequence.
- *
- * Initiator: OWNED => NOPAGE
- * Completer: NOPAGE => OWNED
- */
-static int do_donate(struct pkvm_mem_transition *donation)
-{
- int ret;
-
- ret = check_donation(donation);
- if (ret)
- return ret;
-
- return WARN_ON(__do_donate(donation));
-}
-
int __pkvm_host_share_hyp(u64 pfn)
{
u64 phys = hyp_pfn_to_phys(pfn);
@@ -1865,33 +1592,36 @@ int __pkvm_host_wrprotect_guest(u64 gfn, struct pkvm_hyp_vm *vm)
int __pkvm_host_donate_guest(u64 pfn, u64 gfn, struct pkvm_hyp_vcpu *vcpu)
{
- int ret;
- u64 host_addr = hyp_pfn_to_phys(pfn);
- u64 guest_addr = hyp_pfn_to_phys(gfn);
struct pkvm_hyp_vm *vm = pkvm_hyp_vcpu_to_hyp_vm(vcpu);
- struct pkvm_mem_transition donation = {
- .nr_pages = 1,
- .initiator = {
- .id = PKVM_ID_HOST,
- .addr = host_addr,
- .host = {
- .completer_addr = guest_addr,
- },
- },
- .completer = {
- .id = PKVM_ID_GUEST,
- .guest = {
- .hyp_vcpu = vcpu,
- .phys = host_addr,
- },
- },
- };
+ u64 phys = hyp_pfn_to_phys(pfn);
+ u64 ipa = hyp_pfn_to_phys(gfn);
+ enum kvm_pgtable_prot prot;
+ int ret;
host_lock_component();
guest_lock_component(vm);
- ret = do_donate(&donation);
+ ret = __host_check_page_state_range(phys, PAGE_SIZE, PKVM_PAGE_OWNED);
+ if (ret)
+ goto unlock;
+ ret = __guest_check_page_state_range(vcpu, ipa, PAGE_SIZE, PKVM_NOPAGE);
+ if (ret)
+ goto unlock;
+ WARN_ON(host_stage2_set_owner_locked(phys, PAGE_SIZE, PKVM_ID_GUEST));
+ psci_mem_protect_inc(1);
+ if (pkvm_ipa_range_has_pvmfw(vm, ipa, ipa + PAGE_SIZE)) {
+ ret = pkvm_load_pvmfw_pages(vm, ipa, phys, PAGE_SIZE);
+ if (WARN_ON(ret)) {
+ psci_mem_protect_dec(1);
+ goto unlock;
+ }
+ }
+ prot = pkvm_mkstate(KVM_PGTABLE_PROT_RWX, PKVM_PAGE_OWNED);
+ WARN_ON(kvm_pgtable_stage2_map(&vm->pgt, ipa, PAGE_SIZE, phys, prot,
+ &vcpu->vcpu.arch.stage2_mc, 0));
+
+unlock:
guest_unlock_component(vm);
host_unlock_component();
