* [PATCH 1/3] KVM: arm64: Drop pkvm_mem_transition for FF-A
2025-01-10 12:19 [PATCH 0/3] KVM: arm64: Simplify pKVM memory transitions Quentin Perret
@ 2025-01-10 12:19 ` Quentin Perret
2025-01-10 12:19 ` [PATCH 2/3] KVM: arm64: Drop pkvm_mem_transition for host/hyp sharing Quentin Perret
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: Quentin Perret @ 2025-01-10 12:19 UTC (permalink / raw)
To: Marc Zyngier, Oliver Upton, Joey Gouly, Suzuki K Poulose,
Zenghui Yu, Catalin Marinas, Will Deacon
Cc: Fuad Tabba, Vincent Donnefort, linux-arm-kernel, kvmarm,
linux-kernel
Simplify the __pkvm_host_{un}share_ffa() paths by using
{check,set}_page_state_range().
No functional changes intended.
Signed-off-by: Quentin Perret <qperret@google.com>
---
arch/arm64/kvm/hyp/nvhe/mem_protect.c | 36 ++++++++-------------------
1 file changed, 10 insertions(+), 26 deletions(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index 392f036bc69e..3a3d9fcbc508 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -1324,22 +1324,14 @@ void hyp_unpin_shared_mem(void *from, void *to)
int __pkvm_host_share_ffa(u64 pfn, u64 nr_pages)
{
+ u64 phys = hyp_pfn_to_phys(pfn);
+ u64 size = PAGE_SIZE * 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);
+ ret = __host_check_page_state_range(phys, size, PKVM_PAGE_OWNED);
+ if (!ret)
+ ret = __host_set_page_state_range(phys, size, PKVM_PAGE_SHARED_OWNED);
host_unlock_component();
return ret;
@@ -1347,22 +1339,14 @@ int __pkvm_host_share_ffa(u64 pfn, u64 nr_pages)
int __pkvm_host_unshare_ffa(u64 pfn, u64 nr_pages)
{
+ u64 phys = hyp_pfn_to_phys(pfn);
+ u64 size = PAGE_SIZE * 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);
+ ret = __host_check_page_state_range(phys, size, PKVM_PAGE_SHARED_OWNED);
+ if (!ret)
+ ret = __host_set_page_state_range(phys, size, PKVM_PAGE_OWNED);
host_unlock_component();
return ret;
--
2.47.1.688.g23fc6f90ad-goog
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 2/3] KVM: arm64: Drop pkvm_mem_transition for host/hyp sharing
2025-01-10 12:19 [PATCH 0/3] KVM: arm64: Simplify pKVM memory transitions Quentin Perret
2025-01-10 12:19 ` [PATCH 1/3] KVM: arm64: Drop pkvm_mem_transition for FF-A Quentin Perret
@ 2025-01-10 12:19 ` Quentin Perret
2025-01-10 12:19 ` [PATCH 3/3] KVM: arm64: Drop pkvm_mem_transition for host/hyp donations Quentin Perret
2025-01-12 10:42 ` [PATCH 0/3] KVM: arm64: Simplify pKVM memory transitions Marc Zyngier
3 siblings, 0 replies; 5+ messages in thread
From: Quentin Perret @ 2025-01-10 12:19 UTC (permalink / raw)
To: Marc Zyngier, Oliver Upton, Joey Gouly, Suzuki K Poulose,
Zenghui Yu, Catalin Marinas, Will Deacon
Cc: Fuad Tabba, Vincent Donnefort, linux-arm-kernel, kvmarm,
linux-kernel
Simplify the __pkvm_host_{un}share_hyp() paths by not using the
pkvm_mem_transition machinery. As there are the last users of the
do_share()/do_unshare(), remove all the now-unused code as well.
No functional changes intended.
Signed-off-by: Quentin Perret <qperret@google.com>
---
arch/arm64/kvm/hyp/nvhe/mem_protect.c | 319 +++-----------------------
1 file changed, 34 insertions(+), 285 deletions(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index 3a3d9fcbc508..cd8d233b9527 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -685,36 +685,6 @@ static int host_request_owned_transition(u64 *completer_addr,
return __host_check_page_state_range(addr, size, PKVM_PAGE_OWNED);
}
-static int host_request_unshare(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_SHARED_OWNED);
-}
-
-static int host_initiate_share(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_set_page_state_range(addr, size, PKVM_PAGE_SHARED_OWNED);
-}
-
-static int host_initiate_unshare(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_set_page_state_range(addr, size, PKVM_PAGE_OWNED);
-}
-
static int host_initiate_donation(u64 *completer_addr,
const struct pkvm_mem_transition *tx)
{
@@ -802,31 +772,6 @@ static bool __hyp_ack_skip_pgtable_check(const struct pkvm_mem_transition *tx)
tx->initiator.id != PKVM_ID_HOST);
}
-static int hyp_ack_share(u64 addr, const struct pkvm_mem_transition *tx,
- enum kvm_pgtable_prot perms)
-{
- u64 size = tx->nr_pages * PAGE_SIZE;
-
- if (perms != PAGE_HYP)
- return -EPERM;
-
- if (__hyp_ack_skip_pgtable_check(tx))
- return 0;
-
- return __hyp_check_page_state_range(addr, size, PKVM_NOPAGE);
-}
-
-static int hyp_ack_unshare(u64 addr, const struct pkvm_mem_transition *tx)
-{
- u64 size = tx->nr_pages * PAGE_SIZE;
-
- if (tx->initiator.id == PKVM_ID_HOST && hyp_page_count((void *)addr))
- return -EBUSY;
-
- return __hyp_check_page_state_range(addr, size,
- PKVM_PAGE_SHARED_BORROWED);
-}
-
static int hyp_ack_donation(u64 addr, const struct pkvm_mem_transition *tx)
{
u64 size = tx->nr_pages * PAGE_SIZE;
@@ -837,24 +782,6 @@ static int hyp_ack_donation(u64 addr, const struct pkvm_mem_transition *tx)
return __hyp_check_page_state_range(addr, size, PKVM_NOPAGE);
}
-static int hyp_complete_share(u64 addr, const struct pkvm_mem_transition *tx,
- enum kvm_pgtable_prot perms)
-{
- void *start = (void *)addr, *end = start + (tx->nr_pages * PAGE_SIZE);
- enum kvm_pgtable_prot prot;
-
- prot = pkvm_mkstate(perms, PKVM_PAGE_SHARED_BORROWED);
- return pkvm_create_mappings_locked(start, end, prot);
-}
-
-static int hyp_complete_unshare(u64 addr, const struct pkvm_mem_transition *tx)
-{
- u64 size = tx->nr_pages * PAGE_SIZE;
- int ret = kvm_pgtable_hyp_unmap(&pkvm_pgtable, addr, size);
-
- return (ret != size) ? -EFAULT : 0;
-}
-
static int hyp_complete_donation(u64 addr,
const struct pkvm_mem_transition *tx)
{
@@ -885,180 +812,6 @@ 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 check_share(struct pkvm_mem_share *share)
-{
- const struct pkvm_mem_transition *tx = &share->tx;
- u64 completer_addr;
- int ret;
-
- switch (tx->initiator.id) {
- case PKVM_ID_HOST:
- ret = host_request_owned_transition(&completer_addr, tx);
- break;
- default:
- ret = -EINVAL;
- }
-
- if (ret)
- return ret;
-
- switch (tx->completer.id) {
- case PKVM_ID_HYP:
- ret = hyp_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;
- }
-
- return ret;
-}
-
-static int __do_share(struct pkvm_mem_share *share)
-{
- const struct pkvm_mem_transition *tx = &share->tx;
- u64 completer_addr;
- int ret;
-
- switch (tx->initiator.id) {
- case PKVM_ID_HOST:
- ret = host_initiate_share(&completer_addr, tx);
- break;
- default:
- ret = -EINVAL;
- }
-
- if (ret)
- return ret;
-
- switch (tx->completer.id) {
- case PKVM_ID_HYP:
- ret = hyp_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;
- }
-
- return ret;
-}
-
-/*
- * do_share():
- *
- * The page owner grants access to another component with a given set
- * of permissions.
- *
- * Initiator: OWNED => SHARED_OWNED
- * Completer: NOPAGE => SHARED_BORROWED
- */
-static int do_share(struct pkvm_mem_share *share)
-{
- int ret;
-
- ret = check_share(share);
- if (ret)
- return ret;
-
- return WARN_ON(__do_share(share));
-}
-
-static int check_unshare(struct pkvm_mem_share *share)
-{
- const struct pkvm_mem_transition *tx = &share->tx;
- u64 completer_addr;
- int ret;
-
- switch (tx->initiator.id) {
- case PKVM_ID_HOST:
- ret = host_request_unshare(&completer_addr, tx);
- break;
- default:
- ret = -EINVAL;
- }
-
- if (ret)
- return ret;
-
- switch (tx->completer.id) {
- 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;
- }
-
- return ret;
-}
-
-static int __do_unshare(struct pkvm_mem_share *share)
-{
- const struct pkvm_mem_transition *tx = &share->tx;
- u64 completer_addr;
- int ret;
-
- switch (tx->initiator.id) {
- case PKVM_ID_HOST:
- ret = host_initiate_unshare(&completer_addr, tx);
- break;
- default:
- ret = -EINVAL;
- }
-
- if (ret)
- return ret;
-
- switch (tx->completer.id) {
- 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;
- }
-
- return ret;
-}
-
-/*
- * do_unshare():
- *
- * The page owner revokes access from another component for a range of
- * pages which were previously shared using do_share().
- *
- * Initiator: SHARED_OWNED => OWNED
- * Completer: SHARED_BORROWED => NOPAGE
- */
-static int do_unshare(struct pkvm_mem_share *share)
-{
- int ret;
-
- ret = check_unshare(share);
- if (ret)
- return ret;
-
- return WARN_ON(__do_unshare(share));
-}
-
static int check_donation(struct pkvm_mem_donation *donation)
{
const struct pkvm_mem_transition *tx = &donation->tx;
@@ -1149,31 +902,29 @@ static int do_donate(struct pkvm_mem_donation *donation)
int __pkvm_host_share_hyp(u64 pfn)
{
+ u64 phys = hyp_pfn_to_phys(pfn);
+ void *virt = __hyp_va(phys);
+ enum kvm_pgtable_prot prot;
+ u64 size = PAGE_SIZE;
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,
- .initiator = {
- .id = PKVM_ID_HOST,
- .addr = host_addr,
- .host = {
- .completer_addr = hyp_addr,
- },
- },
- .completer = {
- .id = PKVM_ID_HYP,
- },
- },
- .completer_prot = PAGE_HYP,
- };
host_lock_component();
hyp_lock_component();
- ret = do_share(&share);
+ ret = __host_check_page_state_range(phys, size, PKVM_PAGE_OWNED);
+ if (ret)
+ goto unlock;
+ if (IS_ENABLED(CONFIG_NVHE_EL2_DEBUG)) {
+ ret = __hyp_check_page_state_range((u64)virt, size, PKVM_NOPAGE);
+ if (ret)
+ goto unlock;
+ }
+
+ prot = pkvm_mkstate(PAGE_HYP, PKVM_PAGE_SHARED_BORROWED);
+ WARN_ON(pkvm_create_mappings_locked(virt, virt + size, prot));
+ WARN_ON(__host_set_page_state_range(phys, size, PKVM_PAGE_SHARED_OWNED));
+unlock:
hyp_unlock_component();
host_unlock_component();
@@ -1182,31 +933,29 @@ int __pkvm_host_share_hyp(u64 pfn)
int __pkvm_host_unshare_hyp(u64 pfn)
{
+ u64 phys = hyp_pfn_to_phys(pfn);
+ u64 virt = (u64)__hyp_va(phys);
+ u64 size = PAGE_SIZE;
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,
- .initiator = {
- .id = PKVM_ID_HOST,
- .addr = host_addr,
- .host = {
- .completer_addr = hyp_addr,
- },
- },
- .completer = {
- .id = PKVM_ID_HYP,
- },
- },
- .completer_prot = PAGE_HYP,
- };
host_lock_component();
hyp_lock_component();
- ret = do_unshare(&share);
+ ret = __host_check_page_state_range(phys, size, PKVM_PAGE_SHARED_OWNED);
+ if (ret)
+ goto unlock;
+ ret = __hyp_check_page_state_range(virt, size, PKVM_PAGE_SHARED_BORROWED);
+ if (ret)
+ goto unlock;
+ if (hyp_page_count((void *)virt)) {
+ ret = -EBUSY;
+ goto unlock;
+ }
+
+ WARN_ON(kvm_pgtable_hyp_unmap(&pkvm_pgtable, virt, size) != size);
+ WARN_ON(__host_set_page_state_range(phys, size, PKVM_PAGE_OWNED));
+unlock:
hyp_unlock_component();
host_unlock_component();
--
2.47.1.688.g23fc6f90ad-goog
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH 3/3] KVM: arm64: Drop pkvm_mem_transition for host/hyp donations
2025-01-10 12:19 [PATCH 0/3] KVM: arm64: Simplify pKVM memory transitions Quentin Perret
2025-01-10 12:19 ` [PATCH 1/3] KVM: arm64: Drop pkvm_mem_transition for FF-A Quentin Perret
2025-01-10 12:19 ` [PATCH 2/3] KVM: arm64: Drop pkvm_mem_transition for host/hyp sharing Quentin Perret
@ 2025-01-10 12:19 ` Quentin Perret
2025-01-12 10:42 ` [PATCH 0/3] KVM: arm64: Simplify pKVM memory transitions Marc Zyngier
3 siblings, 0 replies; 5+ messages in thread
From: Quentin Perret @ 2025-01-10 12:19 UTC (permalink / raw)
To: Marc Zyngier, Oliver Upton, Joey Gouly, Suzuki K Poulose,
Zenghui Yu, Catalin Marinas, Will Deacon
Cc: Fuad Tabba, Vincent Donnefort, linux-arm-kernel, kvmarm,
linux-kernel
Simplify the __pkvm_host_donate_hyp() and pkvm_hyp_donate_host() paths
by not using the pkvm_mem_transition machinery. As the last users of
this, also remove all the now unused code.
No functional changes intended.
Signed-off-by: Quentin Perret <qperret@google.com>
---
arch/arm64/kvm/hyp/nvhe/mem_protect.c | 285 +++-----------------------
1 file changed, 32 insertions(+), 253 deletions(-)
diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index cd8d233b9527..7ad7b133b81a 100644
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -583,39 +583,6 @@ void handle_host_mem_abort(struct kvm_cpu_context *host_ctxt)
BUG_ON(ret && ret != -EAGAIN);
}
-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;
- };
- } initiator;
-
- struct {
- enum pkvm_component_id id;
- } completer;
-};
-
-struct pkvm_mem_share {
- const struct pkvm_mem_transition tx;
- const enum kvm_pgtable_prot completer_prot;
-};
-
-struct pkvm_mem_donation {
- const struct pkvm_mem_transition tx;
-};
-
struct check_walk_data {
enum pkvm_page_state desired;
enum pkvm_page_state (*get_page_state)(kvm_pte_t pte, u64 addr);
@@ -675,56 +642,6 @@ 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)
{
if (!kvm_pte_valid(pte))
@@ -745,52 +662,6 @@ 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 = pkvm_mkstate(PAGE_HYP, 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)
{
if (!kvm_pte_valid(pte))
@@ -812,94 +683,6 @@ 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 check_donation(struct pkvm_mem_donation *donation)
-{
- const struct pkvm_mem_transition *tx = &donation->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;
- default:
- ret = -EINVAL;
- }
-
- return ret;
-}
-
-static int __do_donate(struct pkvm_mem_donation *donation)
-{
- const struct pkvm_mem_transition *tx = &donation->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;
- 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_donation *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);
@@ -964,30 +747,29 @@ int __pkvm_host_unshare_hyp(u64 pfn)
int __pkvm_host_donate_hyp(u64 pfn, u64 nr_pages)
{
+ u64 phys = hyp_pfn_to_phys(pfn);
+ u64 size = PAGE_SIZE * nr_pages;
+ void *virt = __hyp_va(phys);
+ enum kvm_pgtable_prot prot;
int ret;
- u64 host_addr = hyp_pfn_to_phys(pfn);
- u64 hyp_addr = (u64)__hyp_va(host_addr);
- struct pkvm_mem_donation donation = {
- .tx = {
- .nr_pages = nr_pages,
- .initiator = {
- .id = PKVM_ID_HOST,
- .addr = host_addr,
- .host = {
- .completer_addr = hyp_addr,
- },
- },
- .completer = {
- .id = PKVM_ID_HYP,
- },
- },
- };
host_lock_component();
hyp_lock_component();
- ret = do_donate(&donation);
+ ret = __host_check_page_state_range(phys, size, PKVM_PAGE_OWNED);
+ if (ret)
+ goto unlock;
+ if (IS_ENABLED(CONFIG_NVHE_EL2_DEBUG)) {
+ ret = __hyp_check_page_state_range((u64)virt, size, PKVM_NOPAGE);
+ if (ret)
+ goto unlock;
+ }
+ prot = pkvm_mkstate(PAGE_HYP, PKVM_PAGE_OWNED);
+ WARN_ON(pkvm_create_mappings_locked(virt, virt + size, prot));
+ WARN_ON(host_stage2_set_owner_locked(phys, size, PKVM_ID_HYP));
+
+unlock:
hyp_unlock_component();
host_unlock_component();
@@ -996,30 +778,27 @@ int __pkvm_host_donate_hyp(u64 pfn, u64 nr_pages)
int __pkvm_hyp_donate_host(u64 pfn, u64 nr_pages)
{
+ u64 phys = hyp_pfn_to_phys(pfn);
+ u64 size = PAGE_SIZE * nr_pages;
+ u64 virt = (u64)__hyp_va(phys);
int ret;
- u64 host_addr = hyp_pfn_to_phys(pfn);
- u64 hyp_addr = (u64)__hyp_va(host_addr);
- struct pkvm_mem_donation donation = {
- .tx = {
- .nr_pages = nr_pages,
- .initiator = {
- .id = PKVM_ID_HYP,
- .addr = hyp_addr,
- .hyp = {
- .completer_addr = host_addr,
- },
- },
- .completer = {
- .id = PKVM_ID_HOST,
- },
- },
- };
host_lock_component();
hyp_lock_component();
- ret = do_donate(&donation);
+ ret = __hyp_check_page_state_range(virt, size, PKVM_PAGE_OWNED);
+ if (ret)
+ goto unlock;
+ if (IS_ENABLED(CONFIG_NVHE_EL2_DEBUG)) {
+ ret = __host_check_page_state_range(phys, size, PKVM_NOPAGE);
+ if (ret)
+ goto unlock;
+ }
+ WARN_ON(kvm_pgtable_hyp_unmap(&pkvm_pgtable, virt, size) != size);
+ WARN_ON(host_stage2_set_owner_locked(phys, size, PKVM_ID_HOST));
+
+unlock:
hyp_unlock_component();
host_unlock_component();
--
2.47.1.688.g23fc6f90ad-goog
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH 0/3] KVM: arm64: Simplify pKVM memory transitions
2025-01-10 12:19 [PATCH 0/3] KVM: arm64: Simplify pKVM memory transitions Quentin Perret
` (2 preceding siblings ...)
2025-01-10 12:19 ` [PATCH 3/3] KVM: arm64: Drop pkvm_mem_transition for host/hyp donations Quentin Perret
@ 2025-01-12 10:42 ` Marc Zyngier
3 siblings, 0 replies; 5+ messages in thread
From: Marc Zyngier @ 2025-01-12 10:42 UTC (permalink / raw)
To: Oliver Upton, Joey Gouly, Suzuki K Poulose, Zenghui Yu,
Catalin Marinas, Will Deacon, Quentin Perret
Cc: Fuad Tabba, Vincent Donnefort, linux-arm-kernel, kvmarm,
linux-kernel
On Fri, 10 Jan 2025 12:19:33 +0000, Quentin Perret wrote:
> Since its early days, pKVM has formalized memory 'transitions' (shares
> and donations) using 'struct pkvm_mem_transition' and bunch of helpers
> to manipulate it. The intention was for all transitions to use this
> machinery to ensure we're checking things consistently. However, as
> development progressed, it became clear that the rigidity of this model
> made it really difficult to use in some use-cases which ended-up
> side-stepping it entirely. That is the case for the
> hyp_{un}pin_shared_mem() and host_{un}share_guest() paths upstream which
> use lower level helpers directly, as well as for several other pKVM
> features that should land upstream in the future (ex: when a guest
> relinquishes a page during ballooning, when annotating a page that is
> being DMA'd to, ...). On top of this, the pkvm_mem_transition machinery
> requires a lot of boilerplate which makes the code hard to read, but
> also adds layers of indirection that no compilers seems to see through,
> hence leading to suboptimal generated code.
>
> [...]
Applied to next, thanks!
[1/3] KVM: arm64: Drop pkvm_mem_transition for FF-A
commit: ed2f80fd76bd2c6e00d2e90f78d21a3055ee3562
[2/3] KVM: arm64: Drop pkvm_mem_transition for host/hyp sharing
commit: d3b3473c15e4391673d8dca9c36dd5e9c3a8a4ac
[3/3] KVM: arm64: Drop pkvm_mem_transition for host/hyp donations
commit: 2d2aa2eb275fa6f80d68ed442c3328273bbbecba
Cheers,
M.
--
Without deviation from the norm, progress is not possible.
^ permalink raw reply [flat|nested] 5+ messages in thread