Re: [PATCH v3 11/36] KVM: arm64: Introduce __pkvm_host_donate_guest()
From: Marc Zyngier <maz@kernel.org>
Date: 2026-03-20 12:38:23
Also in:
kvmarm
On Thu, 05 Mar 2026 14:43:24 +0000, Will Deacon [off-list ref] wrote:
quoted hunk ↗ jump to hunk
In preparation for supporting protected VMs, whose memory pages are isolated from the host, introduce a new pKVM hypercall to allow the donation of pages to a guest. Signed-off-by: Will Deacon <will@kernel.org> --- arch/arm64/include/asm/kvm_asm.h | 1 + arch/arm64/include/asm/kvm_pgtable.h | 2 +- arch/arm64/kvm/hyp/include/nvhe/mem_protect.h | 2 ++ arch/arm64/kvm/hyp/nvhe/hyp-main.c | 21 +++++++++++++ arch/arm64/kvm/hyp/nvhe/mem_protect.c | 30 +++++++++++++++++++ 5 files changed, 55 insertions(+), 1 deletion(-)diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index df6b661701b6..dfc6625c8269 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h@@ -79,6 +79,7 @@ enum __kvm_host_smccc_func { /* Hypercalls that are 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_donate_guest, __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,diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h index c201168f2857..b6f7595c4979 100644 --- a/arch/arm64/include/asm/kvm_pgtable.h +++ b/arch/arm64/include/asm/kvm_pgtable.h@@ -100,7 +100,7 @@ typedef u64 kvm_pte_t; KVM_PTE_LEAF_ATTR_HI_S2_XN) #define KVM_INVALID_PTE_OWNER_MASK GENMASK(9, 2) -#define KVM_MAX_OWNER_ID 1 +#define KVM_MAX_OWNER_ID 3 /* * Used to indicate a pte for which a 'break-before-make' sequence is indiff --git a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h index 5f9d56754e39..9c0cc53d1dc9 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h +++ b/arch/arm64/kvm/hyp/include/nvhe/mem_protect.h@@ -28,6 +28,7 @@ enum pkvm_component_id { PKVM_ID_HOST, PKVM_ID_HYP, PKVM_ID_FFA, + PKVM_ID_GUEST,
Is KVM_MAX_OWNER_ID being set to 3 related to PKVM_ID_GUEST being introduced? If so, wouldn't it be better to define one in terms of the other? Also, this includes PKVM_ID_FFA as a valid ID, while it wasn't included until now. Is that expected? Thanks, M. -- Without deviation from the norm, progress is not possible.