From: Will Deacon <will@kernel.org>
To: kvmarm@lists.linux.dev
Cc: linux-arm-kernel@lists.infradead.org,
Will Deacon <will@kernel.org>, Marc Zyngier <maz@kernel.org>,
Oliver Upton <oupton@kernel.org>, Joey Gouly <joey.gouly@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Zenghui Yu <yuzenghui@huawei.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Quentin Perret <qperret@google.com>,
Fuad Tabba <tabba@google.com>,
Vincent Donnefort <vdonnefort@google.com>,
Mostafa Saleh <smostafa@google.com>
Subject: [PATCH v2 07/35] KVM: arm64: Remove is_protected_kvm_enabled() checks from hypercalls
Date: Mon, 19 Jan 2026 12:46:00 +0000 [thread overview]
Message-ID: <20260119124629.2563-8-will@kernel.org> (raw)
In-Reply-To: <20260119124629.2563-1-will@kernel.org>
When pKVM is not enabled, the host shouldn't issue pKVM-specific
hypercalls and so there's no point checking for this in the pKVM
hypercall handlers.
Remove the redundant is_protected_kvm_enabled() checks from each
hypercall and instead rejig the hypercall table so that the
pKVM-specific hypercalls are unreachable when pKVM is not being used.
Reviewed-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
---
arch/arm64/include/asm/kvm_asm.h | 20 ++++++----
arch/arm64/kvm/hyp/nvhe/hyp-main.c | 63 ++++++++++--------------------
2 files changed, 32 insertions(+), 51 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index a1ad12c72ebf..2076005e9253 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -60,16 +60,9 @@ enum __kvm_host_smccc_func {
__KVM_HOST_SMCCC_FUNC___vgic_v3_init_lrs,
__KVM_HOST_SMCCC_FUNC___vgic_v3_get_gic_config,
__KVM_HOST_SMCCC_FUNC___pkvm_prot_finalize,
+ __KVM_HOST_SMCCC_FUNC_MIN_PKVM = __KVM_HOST_SMCCC_FUNC___pkvm_prot_finalize,
/* Hypercalls available after pKVM finalisation */
- __KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp,
- __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_hyp,
- __KVM_HOST_SMCCC_FUNC___pkvm_host_share_guest,
- __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_guest,
- __KVM_HOST_SMCCC_FUNC___pkvm_host_relax_perms_guest,
- __KVM_HOST_SMCCC_FUNC___pkvm_host_wrprotect_guest,
- __KVM_HOST_SMCCC_FUNC___pkvm_host_test_clear_young_guest,
- __KVM_HOST_SMCCC_FUNC___pkvm_host_mkyoung_guest,
__KVM_HOST_SMCCC_FUNC___kvm_adjust_pc,
__KVM_HOST_SMCCC_FUNC___kvm_vcpu_run,
__KVM_HOST_SMCCC_FUNC___kvm_flush_vm_context,
@@ -81,6 +74,17 @@ enum __kvm_host_smccc_func {
__KVM_HOST_SMCCC_FUNC___kvm_timer_set_cntvoff,
__KVM_HOST_SMCCC_FUNC___vgic_v3_save_aprs,
__KVM_HOST_SMCCC_FUNC___vgic_v3_restore_vmcr_aprs,
+ __KVM_HOST_SMCCC_FUNC_MAX_NO_PKVM = __KVM_HOST_SMCCC_FUNC___vgic_v3_restore_vmcr_aprs,
+
+ /* Hypercalls available only when pKVM has finalised */
+ __KVM_HOST_SMCCC_FUNC___pkvm_host_share_hyp,
+ __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_hyp,
+ __KVM_HOST_SMCCC_FUNC___pkvm_host_share_guest,
+ __KVM_HOST_SMCCC_FUNC___pkvm_host_unshare_guest,
+ __KVM_HOST_SMCCC_FUNC___pkvm_host_relax_perms_guest,
+ __KVM_HOST_SMCCC_FUNC___pkvm_host_wrprotect_guest,
+ __KVM_HOST_SMCCC_FUNC___pkvm_host_test_clear_young_guest,
+ __KVM_HOST_SMCCC_FUNC___pkvm_host_mkyoung_guest,
__KVM_HOST_SMCCC_FUNC___pkvm_reserve_vm,
__KVM_HOST_SMCCC_FUNC___pkvm_unreserve_vm,
__KVM_HOST_SMCCC_FUNC___pkvm_init_vm,
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index a7c689152f68..eb5cfe32b2c9 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -169,9 +169,6 @@ static void handle___pkvm_vcpu_load(struct kvm_cpu_context *host_ctxt)
DECLARE_REG(u64, hcr_el2, host_ctxt, 3);
struct pkvm_hyp_vcpu *hyp_vcpu;
- if (!is_protected_kvm_enabled())
- return;
-
hyp_vcpu = pkvm_load_hyp_vcpu(handle, vcpu_idx);
if (!hyp_vcpu)
return;
@@ -185,12 +182,8 @@ static void handle___pkvm_vcpu_load(struct kvm_cpu_context *host_ctxt)
static void handle___pkvm_vcpu_put(struct kvm_cpu_context *host_ctxt)
{
- struct pkvm_hyp_vcpu *hyp_vcpu;
+ struct pkvm_hyp_vcpu *hyp_vcpu = pkvm_get_loaded_hyp_vcpu();
- if (!is_protected_kvm_enabled())
- return;
-
- hyp_vcpu = pkvm_get_loaded_hyp_vcpu();
if (hyp_vcpu)
pkvm_put_hyp_vcpu(hyp_vcpu);
}
@@ -254,9 +247,6 @@ static void handle___pkvm_host_share_guest(struct kvm_cpu_context *host_ctxt)
struct pkvm_hyp_vcpu *hyp_vcpu;
int ret = -EINVAL;
- if (!is_protected_kvm_enabled())
- goto out;
-
hyp_vcpu = pkvm_get_loaded_hyp_vcpu();
if (!hyp_vcpu || pkvm_hyp_vcpu_is_protected(hyp_vcpu))
goto out;
@@ -278,9 +268,6 @@ static void handle___pkvm_host_unshare_guest(struct kvm_cpu_context *host_ctxt)
struct pkvm_hyp_vm *hyp_vm;
int ret = -EINVAL;
- if (!is_protected_kvm_enabled())
- goto out;
-
hyp_vm = get_np_pkvm_hyp_vm(handle);
if (!hyp_vm)
goto out;
@@ -298,9 +285,6 @@ static void handle___pkvm_host_relax_perms_guest(struct kvm_cpu_context *host_ct
struct pkvm_hyp_vcpu *hyp_vcpu;
int ret = -EINVAL;
- if (!is_protected_kvm_enabled())
- goto out;
-
hyp_vcpu = pkvm_get_loaded_hyp_vcpu();
if (!hyp_vcpu || pkvm_hyp_vcpu_is_protected(hyp_vcpu))
goto out;
@@ -318,9 +302,6 @@ static void handle___pkvm_host_wrprotect_guest(struct kvm_cpu_context *host_ctxt
struct pkvm_hyp_vm *hyp_vm;
int ret = -EINVAL;
- if (!is_protected_kvm_enabled())
- goto out;
-
hyp_vm = get_np_pkvm_hyp_vm(handle);
if (!hyp_vm)
goto out;
@@ -340,9 +321,6 @@ static void handle___pkvm_host_test_clear_young_guest(struct kvm_cpu_context *ho
struct pkvm_hyp_vm *hyp_vm;
int ret = -EINVAL;
- if (!is_protected_kvm_enabled())
- goto out;
-
hyp_vm = get_np_pkvm_hyp_vm(handle);
if (!hyp_vm)
goto out;
@@ -359,9 +337,6 @@ static void handle___pkvm_host_mkyoung_guest(struct kvm_cpu_context *host_ctxt)
struct pkvm_hyp_vcpu *hyp_vcpu;
int ret = -EINVAL;
- if (!is_protected_kvm_enabled())
- goto out;
-
hyp_vcpu = pkvm_get_loaded_hyp_vcpu();
if (!hyp_vcpu || pkvm_hyp_vcpu_is_protected(hyp_vcpu))
goto out;
@@ -421,12 +396,8 @@ static void handle___kvm_tlb_flush_vmid(struct kvm_cpu_context *host_ctxt)
static void handle___pkvm_tlb_flush_vmid(struct kvm_cpu_context *host_ctxt)
{
DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1);
- struct pkvm_hyp_vm *hyp_vm;
+ struct pkvm_hyp_vm *hyp_vm = get_np_pkvm_hyp_vm(handle);
- if (!is_protected_kvm_enabled())
- return;
-
- hyp_vm = get_np_pkvm_hyp_vm(handle);
if (!hyp_vm)
return;
@@ -600,14 +571,6 @@ static const hcall_t host_hcall[] = {
HANDLE_FUNC(__vgic_v3_get_gic_config),
HANDLE_FUNC(__pkvm_prot_finalize),
- HANDLE_FUNC(__pkvm_host_share_hyp),
- HANDLE_FUNC(__pkvm_host_unshare_hyp),
- HANDLE_FUNC(__pkvm_host_share_guest),
- HANDLE_FUNC(__pkvm_host_unshare_guest),
- HANDLE_FUNC(__pkvm_host_relax_perms_guest),
- HANDLE_FUNC(__pkvm_host_wrprotect_guest),
- HANDLE_FUNC(__pkvm_host_test_clear_young_guest),
- HANDLE_FUNC(__pkvm_host_mkyoung_guest),
HANDLE_FUNC(__kvm_adjust_pc),
HANDLE_FUNC(__kvm_vcpu_run),
HANDLE_FUNC(__kvm_flush_vm_context),
@@ -619,6 +582,15 @@ static const hcall_t host_hcall[] = {
HANDLE_FUNC(__kvm_timer_set_cntvoff),
HANDLE_FUNC(__vgic_v3_save_aprs),
HANDLE_FUNC(__vgic_v3_restore_vmcr_aprs),
+
+ HANDLE_FUNC(__pkvm_host_share_hyp),
+ HANDLE_FUNC(__pkvm_host_unshare_hyp),
+ HANDLE_FUNC(__pkvm_host_share_guest),
+ HANDLE_FUNC(__pkvm_host_unshare_guest),
+ HANDLE_FUNC(__pkvm_host_relax_perms_guest),
+ HANDLE_FUNC(__pkvm_host_wrprotect_guest),
+ HANDLE_FUNC(__pkvm_host_test_clear_young_guest),
+ HANDLE_FUNC(__pkvm_host_mkyoung_guest),
HANDLE_FUNC(__pkvm_reserve_vm),
HANDLE_FUNC(__pkvm_unreserve_vm),
HANDLE_FUNC(__pkvm_init_vm),
@@ -632,7 +604,7 @@ static const hcall_t host_hcall[] = {
static void handle_host_hcall(struct kvm_cpu_context *host_ctxt)
{
DECLARE_REG(unsigned long, id, host_ctxt, 0);
- unsigned long hcall_min = 0;
+ unsigned long hcall_min = 0, hcall_max = -1;
hcall_t hfn;
/*
@@ -644,14 +616,19 @@ static void handle_host_hcall(struct kvm_cpu_context *host_ctxt)
* basis. This is all fine, however, since __pkvm_prot_finalize
* returns -EPERM after the first call for a given CPU.
*/
- if (static_branch_unlikely(&kvm_protected_mode_initialized))
- hcall_min = __KVM_HOST_SMCCC_FUNC___pkvm_prot_finalize;
+ if (static_branch_unlikely(&kvm_protected_mode_initialized)) {
+ hcall_min = __KVM_HOST_SMCCC_FUNC_MIN_PKVM;
+ } else {
+ hcall_max = __KVM_HOST_SMCCC_FUNC_MAX_NO_PKVM;
+ }
id &= ~ARM_SMCCC_CALL_HINTS;
id -= KVM_HOST_SMCCC_ID(0);
- if (unlikely(id < hcall_min || id >= ARRAY_SIZE(host_hcall)))
+ if (unlikely(id < hcall_min || id > hcall_max ||
+ id >= ARRAY_SIZE(host_hcall))) {
goto inval;
+ }
hfn = host_hcall[id];
if (unlikely(!hfn))
--
2.52.0.457.g6b5491de43-goog
next prev parent reply other threads:[~2026-01-19 12:47 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-19 12:45 [PATCH v2 00/35] KVM: arm64: Add support for protected guest memory with pKVM Will Deacon
2026-01-19 12:45 ` [PATCH v2 01/35] KVM: arm64: Invert KVM_PGTABLE_WALK_HANDLE_FAULT to fix pKVM walkers Will Deacon
2026-01-19 12:45 ` [PATCH v2 02/35] KVM: arm64: Don't leak stage-2 page-table if VM fails to init under pKVM Will Deacon
2026-01-19 12:45 ` [PATCH v2 03/35] KVM: arm64: Move handle check into pkvm_pgtable_stage2_destroy_range() Will Deacon
2026-01-19 12:45 ` [PATCH v2 04/35] KVM: arm64: Rename __pkvm_pgtable_stage2_unmap() Will Deacon
2026-01-19 12:45 ` [PATCH v2 05/35] KVM: arm64: Don't advertise unsupported features for protected guests Will Deacon
2026-01-19 12:45 ` [PATCH v2 06/35] KVM: arm64: Expose self-hosted debug regs as RAZ/WI " Will Deacon
2026-01-19 12:46 ` Will Deacon [this message]
2026-02-10 14:53 ` [PATCH v2 07/35] KVM: arm64: Remove is_protected_kvm_enabled() checks from hypercalls Alexandru Elisei
2026-03-03 15:45 ` Will Deacon
2026-03-06 11:33 ` Alexandru Elisei
2026-01-19 12:46 ` [PATCH v2 08/35] KVM: arm64: Ignore MMU notifier callbacks for protected VMs Will Deacon
2026-01-19 12:46 ` [PATCH v2 09/35] KVM: arm64: Prevent unsupported memslot operations on " Will Deacon
2026-01-19 12:46 ` [PATCH v2 10/35] KVM: arm64: Ignore -EAGAIN when mapping in pages for the pKVM host Will Deacon
2026-01-19 12:46 ` [PATCH v2 11/35] KVM: arm64: Split teardown hypercall into two phases Will Deacon
2026-01-19 12:46 ` [PATCH v2 12/35] KVM: arm64: Introduce __pkvm_host_donate_guest() Will Deacon
2026-01-19 12:46 ` [PATCH v2 13/35] KVM: arm64: Hook up donation hypercall to pkvm_pgtable_stage2_map() Will Deacon
2026-01-19 12:46 ` [PATCH v2 14/35] KVM: arm64: Handle aborts from protected VMs Will Deacon
2026-02-12 10:37 ` Alexandru Elisei
2026-03-04 14:06 ` Will Deacon
2026-03-06 11:34 ` Alexandru Elisei
2026-03-11 10:24 ` Fuad Tabba
2026-01-19 12:46 ` [PATCH v2 15/35] KVM: arm64: Introduce __pkvm_reclaim_dying_guest_page() Will Deacon
2026-01-19 12:46 ` [PATCH v2 16/35] KVM: arm64: Hook up reclaim hypercall to pkvm_pgtable_stage2_destroy() Will Deacon
2026-01-19 12:46 ` [PATCH v2 17/35] KVM: arm64: Refactor enter_exception64() Will Deacon
2026-01-19 12:46 ` [PATCH v2 18/35] KVM: arm64: Inject SIGSEGV on illegal accesses Will Deacon
2026-01-19 12:46 ` [PATCH v2 19/35] KVM: arm64: Avoid pointless annotation when mapping host-owned pages Will Deacon
2026-01-19 12:46 ` [PATCH v2 20/35] KVM: arm64: Generalise kvm_pgtable_stage2_set_owner() Will Deacon
2026-01-19 12:46 ` [PATCH v2 21/35] KVM: arm64: Introduce host_stage2_set_owner_metadata_locked() Will Deacon
2026-01-19 12:46 ` [PATCH v2 22/35] KVM: arm64: Change 'pkvm_handle_t' to u16 Will Deacon
2026-01-28 10:28 ` Fuad Tabba
2026-01-19 12:46 ` [PATCH v2 23/35] KVM: arm64: Annotate guest donations with handle and gfn in host stage-2 Will Deacon
2026-01-28 10:29 ` Fuad Tabba
2026-01-19 12:46 ` [PATCH v2 24/35] KVM: arm64: Introduce hypercall to force reclaim of a protected page Will Deacon
2026-02-12 17:18 ` Alexandru Elisei
2026-03-04 14:08 ` Will Deacon
2026-01-19 12:46 ` [PATCH v2 25/35] KVM: arm64: Reclaim faulting page from pKVM in spurious fault handler Will Deacon
2026-02-12 17:22 ` Alexandru Elisei
2026-03-04 14:06 ` Will Deacon
2026-01-19 12:46 ` [PATCH v2 26/35] KVM: arm64: Return -EFAULT from VCPU_RUN on access to a poisoned pte Will Deacon
2026-01-19 12:46 ` [PATCH v2 27/35] KVM: arm64: Add hvc handler at EL2 for hypercalls from protected VMs Will Deacon
2026-01-19 12:46 ` [PATCH v2 28/35] KVM: arm64: Implement the MEM_SHARE hypercall for " Will Deacon
2026-01-19 12:46 ` [PATCH v2 29/35] KVM: arm64: Implement the MEM_UNSHARE " Will Deacon
2026-01-19 12:46 ` [PATCH v2 30/35] KVM: arm64: Allow userspace to create protected VMs when pKVM is enabled Will Deacon
2026-01-19 12:46 ` [PATCH v2 31/35] KVM: arm64: Add some initial documentation for pKVM Will Deacon
2026-01-19 12:46 ` [PATCH v2 32/35] KVM: arm64: Extend pKVM page ownership selftests to cover guest donation Will Deacon
2026-01-19 12:46 ` [PATCH v2 33/35] KVM: arm64: Register 'selftest_vm' in the VM table Will Deacon
2026-01-19 12:46 ` [PATCH v2 34/35] KVM: arm64: Extend pKVM page ownership selftests to cover forced reclaim Will Deacon
2026-01-19 12:46 ` [PATCH v2 35/35] KVM: arm64: Extend pKVM page ownership selftests to cover guest hvcs Will Deacon
2026-02-10 18:58 ` [PATCH v2 00/35] KVM: arm64: Add support for protected guest memory with pKVM Trilok Soni
2026-02-10 19:03 ` Fuad Tabba
2026-02-16 10:58 ` Venkata Rao Kakani
2026-02-16 11:00 ` Fuad Tabba
2026-02-17 10:43 ` Venkata Rao Kakani
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