From: Gavin Shan <gshan@redhat•com>
To: Steven Price <steven.price@arm•com>,
kvm@vger•kernel.org, kvmarm@lists•linux.dev
Cc: Catalin Marinas <catalin.marinas@arm•com>,
Marc Zyngier <maz@kernel•org>, Will Deacon <will@kernel•org>,
James Morse <james.morse@arm•com>,
Oliver Upton <oliver.upton@linux•dev>,
Suzuki K Poulose <suzuki.poulose@arm•com>,
Zenghui Yu <yuzenghui@huawei•com>,
linux-arm-kernel@lists•infradead.org,
linux-kernel@vger•kernel.org, Joey Gouly <joey.gouly@arm•com>,
Alexandru Elisei <alexandru.elisei@arm•com>,
Christoffer Dall <christoffer.dall@arm•com>,
Fuad Tabba <tabba@google•com>,
linux-coco@lists•linux.dev,
Ganapatrao Kulkarni <gankulkarni@os•amperecomputing.com>,
Shanker Donthineni <sdonthineni@nvidia•com>,
Alper Gun <alpergun@google•com>,
"Aneesh Kumar K . V" <aneesh.kumar@kernel•org>,
Emi Kisanuki <fj0570is@fujitsu•com>,
Vishal Annapurve <vannapurve@google•com>,
WeiLin.Chang@arm•com, Lorenzo.Pieralisi2@arm•com
Subject: Re: [PATCH v14 26/44] arm64: RMI: Allow populating initial contents
Date: Thu, 28 May 2026 15:30:19 +1000 [thread overview]
Message-ID: <ea4be6c5-9506-4253-80c5-c76c9ac3b77d@redhat.com> (raw)
In-Reply-To: <20260513131757.116630-27-steven.price@arm.com>
Hi Steve,
On 5/13/26 11:17 PM, Steven Price wrote:
> The VMM needs to populate the realm with some data before starting (e.g.
> a kernel and initrd). This is measured by the RMM and used as part of
> the attestation later on.
>
> Signed-off-by: Steven Price <steven.price@arm•com>
> ---
> Changes since v13:
> * Rename realm_create_protected_data_page() to realm_data_map_init().
> Changes since v12:
> * The ioctl now updates the structure with the amount populated rather
> than returning this through the ioctl return code.
> * Use the new RMM v2.0 range based RMI calls.
> * Adapt to upstream changes in kvm_gmem_populate().
> Changes since v11:
> * The multiplex CAP is gone and there's a new ioctl which makes use of
> the generic kvm_gmem_populate() functionality.
> Changes since v7:
> * Improve the error codes.
> * Other minor changes from review.
> Changes since v6:
> * Handle host potentially having a larger page size than the RMM
> granule.
> * Drop historic "par" (protected address range) from
> populate_par_region() - it doesn't exist within the current
> architecture.
> * Add a cond_resched() call in kvm_populate_realm().
> Changes since v5:
> * Refactor to use PFNs rather than tracking struct page in
> realm_create_protected_data_page().
> * Pull changes from a later patch (in the v5 series) for accessing
> pages from a guest memfd.
> * Do the populate in chunks to avoid holding locks for too long and
> triggering RCU stall warnings.
> ---
> arch/arm64/include/asm/kvm_rmi.h | 4 ++
> arch/arm64/kvm/Kconfig | 1 +
> arch/arm64/kvm/arm.c | 13 ++++
> arch/arm64/kvm/rmi.c | 106 +++++++++++++++++++++++++++++++
> 4 files changed, 124 insertions(+)
>
> diff --git a/arch/arm64/include/asm/kvm_rmi.h b/arch/arm64/include/asm/kvm_rmi.h
> index 007249a13dbc..a2b6bc412a22 100644
> --- a/arch/arm64/include/asm/kvm_rmi.h
> +++ b/arch/arm64/include/asm/kvm_rmi.h
> @@ -88,6 +88,10 @@ int kvm_rec_enter(struct kvm_vcpu *vcpu);
> int kvm_rec_pre_enter(struct kvm_vcpu *vcpu);
> int handle_rec_exit(struct kvm_vcpu *vcpu, int rec_run_status);
>
> +struct kvm_arm_rmi_populate;
> +
> +int kvm_arm_rmi_populate(struct kvm *kvm,
> + struct kvm_arm_rmi_populate *arg);
> void kvm_realm_unmap_range(struct kvm *kvm,
> unsigned long ipa,
> unsigned long size,
> diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
> index 4e16719fda22..d0cd011cf672 100644
> --- a/arch/arm64/kvm/Kconfig
> +++ b/arch/arm64/kvm/Kconfig
> @@ -38,6 +38,7 @@ menuconfig KVM
> select GUEST_PERF_EVENTS if PERF_EVENTS
> select KVM_GUEST_MEMFD
> select KVM_GENERIC_MEMORY_ATTRIBUTES
> + select HAVE_KVM_ARCH_GMEM_POPULATE
> help
> Support hosting virtualized guest machines.
>
> diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
> index ed88a203b892..073ba9181da9 100644
> --- a/arch/arm64/kvm/arm.c
> +++ b/arch/arm64/kvm/arm.c
> @@ -2131,6 +2131,19 @@ int kvm_arch_vm_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
> return -EFAULT;
> return kvm_vm_ioctl_get_reg_writable_masks(kvm, &range);
> }
> + case KVM_ARM_RMI_POPULATE: {
> + struct kvm_arm_rmi_populate req;
> + int ret;
> +
> + if (!kvm_is_realm(kvm))
> + return -ENXIO;
> + if (copy_from_user(&req, argp, sizeof(req)))
> + return -EFAULT;
> + ret = kvm_arm_rmi_populate(kvm, &req);
> + if (copy_to_user(argp, &req, sizeof(req)))
> + return -EFAULT;
> + return ret;
> + }
s/return ret/return 0; The variable 'ret' can be dropped.
> default:
> return -EINVAL;
> }
> diff --git a/arch/arm64/kvm/rmi.c b/arch/arm64/kvm/rmi.c
> index a89873a5eb77..209087bcf399 100644
> --- a/arch/arm64/kvm/rmi.c
> +++ b/arch/arm64/kvm/rmi.c
> @@ -486,6 +486,75 @@ void kvm_realm_unmap_range(struct kvm *kvm, unsigned long start,
> realm_unmap_private_range(kvm, start, end, may_block);
> }
>
> +static int realm_data_map_init(struct kvm *kvm, unsigned long ipa,
> + kvm_pfn_t dst_pfn, kvm_pfn_t src_pfn,
> + unsigned long flags)
> +{
> + struct realm *realm = &kvm->arch.realm;
> + phys_addr_t rd = virt_to_phys(realm->rd);
> + phys_addr_t dst_phys, src_phys;
> + int ret;
> +
> + dst_phys = __pfn_to_phys(dst_pfn);
> + src_phys = __pfn_to_phys(src_pfn);
> +
> + if (rmi_delegate_page(dst_phys))
> + return -ENXIO;
> +
> + ret = rmi_rtt_data_map_init(rd, dst_phys, ipa, src_phys, flags);
> + if (RMI_RETURN_STATUS(ret) == RMI_ERROR_RTT) {
> + /* Create missing RTTs and retry */
> + int level = RMI_RETURN_INDEX(ret);
> +
> + KVM_BUG_ON(level == KVM_PGTABLE_LAST_LEVEL, kvm);
KVM_BUG_ON(level >= KVM_PGTABLE_LAST_LEVEL, kvm);> +
> + ret = realm_create_rtt_levels(realm, ipa, level,
> + KVM_PGTABLE_LAST_LEVEL, NULL);
> + if (!ret) {
> + ret = rmi_rtt_data_map_init(rd, dst_phys, ipa, src_phys,
> + flags);
> + }
> + }
> +
> + if (ret) {
> + if (WARN_ON(rmi_undelegate_page(dst_phys))) {
> + /* Undelegate failed, so we leak the page */
> + get_page(pfn_to_page(dst_pfn));
> + }
> + }
> +
if (ret && WARN_ON(rmi_undelegate_page(dst_phys)) {
/* Leak the page that fails to be undelegated */
get_page(pfn_to_page(dst_pfn));
}
> + return ret;
> +}
> +
> +static int populate_region_cb(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn,
> + struct page *src_page, void *opaque)
> +{
> + unsigned long data_flags = *(unsigned long *)opaque;
> + phys_addr_t ipa = gfn_to_gpa(gfn);
> +
> + if (!src_page)
> + return -EOPNOTSUPP;
> +
> + return realm_data_map_init(kvm, ipa, pfn, page_to_pfn(src_page),
> + data_flags);
> +}
> +
> +static long populate_region(struct kvm *kvm,
> + gfn_t base_gfn,
> + unsigned long pages,
> + u64 uaddr,
> + unsigned long data_flags)
> +{
> + long ret = 0;
> +
> + mutex_lock(&kvm->slots_lock);
> + ret = kvm_gmem_populate(kvm, base_gfn, u64_to_user_ptr(uaddr), pages,
> + populate_region_cb, &data_flags);
> + mutex_unlock(&kvm->slots_lock);
> +
> + return ret;
> +}
> +
> enum ripas_action {
> RIPAS_INIT,
> RIPAS_SET,
> @@ -574,6 +643,43 @@ static int realm_ensure_created(struct kvm *kvm)
> return -ENXIO;
> }
>
> +int kvm_arm_rmi_populate(struct kvm *kvm,
> + struct kvm_arm_rmi_populate *args)
> +{
> + unsigned long data_flags = 0;
> + unsigned long ipa_start = args->base;
> + unsigned long ipa_end = ipa_start + args->size;
> + long pages_populated;
> + int ret;
> +
> + if (args->reserved ||
> + (args->flags & ~KVM_ARM_RMI_POPULATE_FLAGS_MEASURE) ||
> + !IS_ALIGNED(ipa_start, PAGE_SIZE) ||
> + !IS_ALIGNED(ipa_end, PAGE_SIZE) ||
> + !IS_ALIGNED(args->source_uaddr, PAGE_SIZE))
> + return -EINVAL;
> +
There are more conditions missed here:
args->size == 0, return 0;
args->base + args->size < args->base, return -EINVAL; // wrapped range
> + ret = realm_ensure_created(kvm);
> + if (ret)
> + return ret;
> +
> + if (args->flags & KVM_ARM_RMI_POPULATE_FLAGS_MEASURE)
> + data_flags |= RMI_MEASURE_CONTENT;
> +
> + pages_populated = populate_region(kvm, gpa_to_gfn(ipa_start),
> + args->size >> PAGE_SHIFT,
> + args->source_uaddr, data_flags);
> +
> + if (pages_populated < 0)
> + return pages_populated;
pages_populaged is 'unsigned long', this function returns a 'int' value.
> +
> + args->size -= pages_populated << PAGE_SHIFT;
> + args->source_uaddr += pages_populated << PAGE_SHIFT;
> + args->base += pages_populated << PAGE_SHIFT;
> +
> + return 0;
> +}
> +
> static void kvm_complete_ripas_change(struct kvm_vcpu *vcpu)
> {
> struct kvm *kvm = vcpu->kvm;
Thanks,
Gavin
next prev parent reply other threads:[~2026-05-28 5:30 UTC|newest]
Thread overview: 124+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-13 13:17 [PATCH v14 00/44] arm64: Support for Arm CCA in KVM Steven Price
2026-05-13 13:17 ` [PATCH v14 01/44] kvm: arm64: Include kvm_emulate.h in kvm/arm_psci.h Steven Price
2026-05-21 10:19 ` Marc Zyngier
2026-05-21 15:11 ` Steven Price
2026-05-13 13:17 ` [PATCH v14 02/44] kvm: arm64: Avoid including linux/kvm_host.h in kvm_pgtable.h Steven Price
2026-05-21 10:26 ` Marc Zyngier
2026-05-21 15:11 ` Steven Price
2026-05-13 13:17 ` [PATCH v14 03/44] arm64: RME: Handle Granule Protection Faults (GPFs) Steven Price
2026-05-21 12:25 ` Marc Zyngier
2026-05-21 15:15 ` Steven Price
2026-05-13 13:17 ` [PATCH v14 04/44] arm64: RMI: Add SMC definitions for calling the RMM Steven Price
2026-05-18 7:08 ` Gavin Shan
2026-05-20 16:01 ` Steven Price
2026-05-21 12:40 ` Marc Zyngier
2026-05-21 14:50 ` Suzuki K Poulose
2026-05-21 15:33 ` Steven Price
2026-05-22 9:58 ` Marc Zyngier
2026-06-03 10:15 ` Steven Price
2026-05-13 13:17 ` [PATCH v14 05/44] arm64: RMI: Add wrappers for RMI calls Steven Price
2026-05-19 5:35 ` Aneesh Kumar K.V
2026-05-21 15:44 ` Steven Price
2026-05-21 0:21 ` Gavin Shan
2026-05-21 15:44 ` Steven Price
2026-05-21 12:49 ` Marc Zyngier
2026-05-21 15:44 ` Steven Price
2026-05-13 13:17 ` [PATCH v14 06/44] arm64: RMI: Check for RMI support at init Steven Price
2026-05-21 0:39 ` Gavin Shan
2026-05-21 15:49 ` Steven Price
2026-05-25 6:58 ` Gavin Shan
2026-06-03 10:57 ` Steven Price
2026-05-21 13:02 ` Marc Zyngier
2026-06-03 10:57 ` Steven Price
2026-05-13 13:17 ` [PATCH v14 07/44] arm64: RMI: Configure the RMM with the host's page size Steven Price
2026-05-21 0:51 ` Gavin Shan
2026-05-21 22:36 ` Suzuki K Poulose
2026-05-21 13:30 ` Marc Zyngier
2026-05-21 14:53 ` Suzuki K Poulose
2026-06-03 15:48 ` Steven Price
2026-05-13 13:17 ` [PATCH v14 08/44] arm64: RMI: Ensure that the RMM has GPT entries for memory Steven Price
2026-05-19 5:55 ` Aneesh Kumar K.V
2026-06-03 15:48 ` Steven Price
2026-05-21 0:58 ` Gavin Shan
2026-06-03 15:48 ` Steven Price
2026-05-21 13:47 ` Marc Zyngier
2026-05-21 14:24 ` Marc Zyngier
2026-05-21 15:39 ` Suzuki K Poulose
2026-06-03 15:48 ` Steven Price
2026-05-13 13:17 ` [PATCH v14 09/44] arm64: RMI: Provide functions to delegate/undelegate ranges of memory Steven Price
2026-05-21 13:59 ` Marc Zyngier
2026-05-21 16:01 ` Suzuki K Poulose
2026-05-22 10:02 ` Marc Zyngier
2026-06-04 14:43 ` Steven Price
2026-05-13 13:17 ` [PATCH v14 10/44] arm64: RMI: Add support for SRO Steven Price
2026-05-14 8:01 ` Aneesh Kumar K.V
2026-05-14 9:33 ` Steven Price
2026-05-19 6:02 ` Aneesh Kumar K.V
2026-06-04 15:19 ` Steven Price
2026-05-21 4:38 ` Gavin Shan
2026-06-04 15:19 ` Steven Price
2026-05-21 14:35 ` Marc Zyngier
2026-06-04 15:19 ` Steven Price
2026-05-13 13:17 ` [PATCH v14 11/44] arm64: RMI: Check for RMI support at KVM init Steven Price
2026-05-13 13:17 ` [PATCH v14 12/44] arm64: RMI: Check for LPA2 support Steven Price
2026-05-13 13:17 ` [PATCH v14 13/44] arm64: RMI: Define the user ABI Steven Price
2026-05-26 22:17 ` Wei-Lin Chang
2026-06-04 15:27 ` Steven Price
2026-05-27 15:21 ` Marc Zyngier
2026-06-02 11:15 ` Suzuki K Poulose
2026-06-04 15:27 ` Steven Price
2026-05-13 13:17 ` [PATCH v14 14/44] arm64: RMI: Basic infrastructure for creating a realm Steven Price
2026-05-19 6:31 ` Aneesh Kumar K.V
2026-05-28 7:10 ` Marc Zyngier
2026-06-02 14:49 ` Suzuki K Poulose
2026-06-04 15:55 ` Steven Price
2026-05-13 13:17 ` [PATCH v14 15/44] kvm: arm64: Don't expose unsupported capabilities for realm guests Steven Price
2026-05-13 13:17 ` [PATCH v14 16/44] KVM: arm64: Allow passing machine type in KVM creation Steven Price
2026-05-13 13:17 ` [PATCH v14 17/44] arm64: RMI: RTT tear down Steven Price
2026-05-19 6:54 ` Aneesh Kumar K.V
2026-05-26 22:27 ` Wei-Lin Chang
2026-05-26 22:32 ` Wei-Lin Chang
2026-05-13 13:17 ` [PATCH v14 18/44] arm64: RMI: Activate realm on first VCPU run Steven Price
2026-05-13 13:17 ` [PATCH v14 19/44] arm64: RMI: Allocate/free RECs to match vCPUs Steven Price
2026-05-26 22:39 ` Wei-Lin Chang
2026-05-13 13:17 ` [PATCH v14 20/44] arm64: RMI: Support for the VGIC in realms Steven Price
2026-05-28 4:07 ` Gavin Shan
2026-05-13 13:17 ` [PATCH v14 21/44] KVM: arm64: Support timers in realm RECs Steven Price
2026-05-28 4:11 ` Gavin Shan
2026-05-13 13:17 ` [PATCH v14 22/44] arm64: RMI: Handle realm enter/exit Steven Price
2026-05-28 4:38 ` Gavin Shan
2026-05-13 13:17 ` [PATCH v14 23/44] arm64: RMI: Handle RMI_EXIT_RIPAS_CHANGE Steven Price
2026-05-19 9:40 ` Aneesh Kumar K.V
2026-05-27 10:52 ` Wei-Lin Chang
2026-05-13 13:17 ` [PATCH v14 24/44] KVM: arm64: Handle realm MMIO emulation Steven Price
2026-05-28 5:03 ` Gavin Shan
2026-05-13 13:17 ` [PATCH v14 25/44] KVM: arm64: Expose support for private memory Steven Price
2026-05-13 13:17 ` [PATCH v14 26/44] arm64: RMI: Allow populating initial contents Steven Price
2026-05-28 5:30 ` Gavin Shan [this message]
2026-05-13 13:17 ` [PATCH v14 27/44] arm64: RMI: Set RIPAS of initial memslots Steven Price
2026-05-19 10:02 ` Aneesh Kumar K.V
2026-05-19 10:13 ` Suzuki K Poulose
2026-05-19 12:55 ` Aneesh Kumar K.V
2026-05-19 13:06 ` Suzuki K Poulose
2026-05-13 13:17 ` [PATCH v14 28/44] arm64: RMI: Create the realm descriptor Steven Price
2026-05-26 22:47 ` Wei-Lin Chang
2026-05-28 5:51 ` Gavin Shan
2026-05-13 13:17 ` [PATCH v14 29/44] arm64: RMI: Runtime faulting of memory Steven Price
2026-06-05 6:23 ` Gavin Shan
2026-05-13 13:17 ` [PATCH v14 30/44] KVM: arm64: Handle realm VCPU load Steven Price
2026-05-13 13:17 ` [PATCH v14 31/44] KVM: arm64: Validate register access for a Realm VM Steven Price
2026-05-13 13:17 ` [PATCH v14 32/44] KVM: arm64: Handle Realm PSCI requests Steven Price
2026-05-28 6:55 ` Gavin Shan
2026-05-13 13:17 ` [PATCH v14 33/44] KVM: arm64: WARN on injected undef exceptions Steven Price
2026-05-13 13:17 ` [PATCH v14 34/44] arm64: RMI: allow userspace to inject aborts Steven Price
2026-05-13 13:17 ` [PATCH v14 35/44] arm64: RMI: support RSI_HOST_CALL Steven Price
2026-05-13 13:17 ` [PATCH v14 36/44] arm64: RMI: Allow checking SVE on VM instance Steven Price
2026-05-13 13:17 ` [PATCH v14 37/44] arm64: RMI: Prevent Device mappings for Realms Steven Price
2026-05-19 10:25 ` Aneesh Kumar K.V
2026-05-13 13:17 ` [PATCH v14 38/44] arm64: RMI: Propagate number of breakpoints and watchpoints to userspace Steven Price
2026-05-13 13:17 ` [PATCH v14 39/44] arm64: RMI: Set breakpoint parameters through SET_ONE_REG Steven Price
2026-05-13 13:17 ` [PATCH v14 40/44] arm64: RMI: Propagate max SVE vector length from RMM Steven Price
2026-05-13 13:17 ` [PATCH v14 41/44] arm64: RMI: Configure max SVE vector length for a Realm Steven Price
2026-05-13 13:17 ` [PATCH v14 42/44] arm64: RMI: Provide register list for unfinalized RMI RECs Steven Price
2026-05-13 13:17 ` [PATCH v14 43/44] arm64: RMI: Provide accurate register list Steven Price
2026-05-13 13:17 ` [PATCH v14 44/44] arm64: RMI: Enable realms to be created Steven Price
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