From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C7E72CD4F3D for ; Wed, 20 May 2026 15:27:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:Cc:To:From: Subject:Message-ID:References:Mime-Version:In-Reply-To:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=2dP/J1DbhtLVImQPHdjjhVild5BKkbbGQM9cLmZs/I0=; b=a0Mx5GBWVFOG5Imv3LUfiWn7Wk iA1usobW5QDezYqGGWP1of+gtuJx82ECg1F5g3hcc6h6h6z2FzAHh6VMR1wCscG2zIG/a8gn8qGcE S25XlMRbWY0KQLoJl3E6EiFp9QtIrOso+PG3tzeVc2OF95FgZqp4lUwZYOT0+GONNzh7FCg8YcR1E uabUHUwjaJSJmHuOGnOkka+cMqTJAjaYkiQJ5WfLE56E8Zyw0N+eG9GI342x45PLE7jxt8UPOI3R+ VsyNjFM59NPTtdonLCdAgVaTEmzdHv0iagu++moewm6VYcWx+iJtgw6/52t/SCkVITY0TSiyzpjak LFl9nncQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wPipj-00000004zIv-0QZm; Wed, 20 May 2026 15:27:43 +0000 Received: from mail-wr1-f73.google.com ([209.85.221.73]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wPipS-00000004z3T-3539 for linux-arm-kernel@lists.infradead.org; Wed, 20 May 2026 15:27:28 +0000 Received: by mail-wr1-f73.google.com with SMTP id ffacd0b85a97d-45e2f74da10so5561812f8f.2 for ; Wed, 20 May 2026 08:27:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1779290844; x=1779895644; darn=lists.infradead.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=2dP/J1DbhtLVImQPHdjjhVild5BKkbbGQM9cLmZs/I0=; b=txrvZxp//BZB/B/B49DMu/EWoV3mypncbPOQTheL7A1vMAhYOMNhorzXXZiB8AQzlR pBoEZEx5ABLt8f8MZUy+5vPeL9BE7gIQawcHp9rvraRl9oq/6I4LakciK8PYj3jPHUio uBnH2Y/KfXTKxM7GnuH+nqNtHcBI+wwMH1teGq8oMf/ex43YYOjkjfcyY/xe0/qXmFFL nheUr9jCkcocleLdZ9ensPYLVKZDaArNPiFZRNe/RmS54Cj3JHDZXuMTfjOz78kzPyTm /Bfy1DTh1UxVRVVjlmSe6mhAcWSgJd+WUgb+CqvqMLacW6c7UbcNaTHucKAeJXBljoYC lFyQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1779290844; x=1779895644; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=2dP/J1DbhtLVImQPHdjjhVild5BKkbbGQM9cLmZs/I0=; b=bflIfUS5A15Omu5C15ciKQiqdfepqPvlOEPUuV8oEIuD0uqXSA0pGpP8qL3NvVdm5p RbAcxSQF08RElUWbdxXM51kvjRMeEYmogIDKYEXYttWKjjl/3pVFtU1QeQJEoZakkmgV 4p/wLRMlxF95sKo0kVqIOE4zRqCZDKISH5EL24Mf6UxV7Zm9c4Edd/QVkprNqr80Imc5 ydTpTjXfNKG+Ri+TedRFDkhbTLAvysHPYZ+4SBK+8i431ZoZ5QKbIg0K5wkcbfRI+0Uh tlkIIhbzSL54mT74aScm0kHp4vw2k6c5ogWuIVrp6oKqZhBq0bioFSuiMJ9rHwj36KDs +x/w== X-Gm-Message-State: AOJu0Yx4TbeB0J1u/NwrK7E01QfRhRM7sQAuuHKfWOfAEZW8gWVD1MPS DVWES0dn2UG+Dfr1HHG7xdH2hSv68CRXjAWK97a3AoCX9SLYY6uq+ZUPUMjfpTpdkNqGTTzZObE xKWeOqW8OuSVXAII5AtGnBQ== X-Received: from wmbdt12.prod.google.com ([2002:a05:600c:630c:b0:488:b96e:9939]) (user=vdonnefort job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:3b26:b0:490:261d:7dfe with SMTP id 5b1f17b1804b1-490261d7e2bmr80484455e9.6.1779290843643; Wed, 20 May 2026 08:27:23 -0700 (PDT) Date: Wed, 20 May 2026 16:26:42 +0100 In-Reply-To: <20260520152650.4107895-1-vdonnefort@google.com> Mime-Version: 1.0 References: <20260520152650.4107895-1-vdonnefort@google.com> X-Mailer: git-send-email 2.54.0.631.ge1b05301d1-goog Message-ID: <20260520152650.4107895-10-vdonnefort@google.com> Subject: [PATCH 09/17] KVM: arm64: Add reclaim interface for the pKVM heap alloc From: Vincent Donnefort To: maz@kernel.org, oliver.upton@linux.dev, joey.gouly@arm.com, suzuki.poulose@arm.com, yuzenghui@huawei.com, catalin.marinas@arm.com, will@kernel.org Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kernel-team@android.com, qperret@google.com, tabba@google.com, Vincent Donnefort Content-Type: text/plain; charset="UTF-8" X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260520_082726_797204_0EBCAF38 X-CRM114-Status: GOOD ( 12.43 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Introduce a host interface to reclaim donated memory from the pKVM heap allocator back to the host. It specifically provides two helpers that will make it easier to create a shrinker for pKVM: pkvm_hyp_reclaimable() pkvm_hyp_relaim() Signed-off-by: Vincent Donnefort diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index 681b7bf8ac08..b427ef790b15 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -115,6 +115,8 @@ enum __kvm_host_smccc_func { __KVM_HOST_SMCCC_FUNC___pkvm_vcpu_put, __KVM_HOST_SMCCC_FUNC___pkvm_tlb_flush_vmid, __KVM_HOST_SMCCC_FUNC___pkvm_hyp_topup, + __KVM_HOST_SMCCC_FUNC___pkvm_hyp_reclaim, + __KVM_HOST_SMCCC_FUNC___pkvm_hyp_reclaimable, MARKER(__KVM_HOST_SMCCC_FUNC_MAX) }; diff --git a/arch/arm64/include/asm/kvm_pkvm.h b/arch/arm64/include/asm/kvm_pkvm.h index bf43235e62d3..ca3b5fc5f28f 100644 --- a/arch/arm64/include/asm/kvm_pkvm.h +++ b/arch/arm64/include/asm/kvm_pkvm.h @@ -21,6 +21,9 @@ enum pkvm_topup_id { PKVM_TOPUP_HYP_ALLOC, }; +unsigned long pkvm_hyp_reclaim(enum pkvm_topup_id id, unsigned long target); +unsigned long pkvm_hyp_reclaimable(enum pkvm_topup_id id); + int pkvm_init_host_vm(struct kvm *kvm, unsigned long type); int pkvm_create_hyp_vm(struct kvm *kvm); bool pkvm_hyp_vm_is_created(struct kvm *kvm); diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 38ce834ca840..20be0343abd4 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -638,6 +638,42 @@ static void handle___pkvm_hyp_topup(struct kvm_cpu_context *host_ctxt) cpu_reg(host_ctxt, 3) = host_mc.nr_pages; } +static void handle___pkvm_hyp_reclaim(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(enum pkvm_topup_id, id, host_ctxt, 1); + DECLARE_REG(unsigned long, target, host_ctxt, 2); + struct kvm_hyp_memcache host_mc = {}; + int ret = 0; + + switch (id) { + case PKVM_TOPUP_HYP_ALLOC: + hyp_alloc_reclaim(&host_mc, target); + break; + default: + ret = -EINVAL; + } + + cpu_reg(host_ctxt, 1) = ret; + cpu_reg(host_ctxt, 2) = host_mc.head; + cpu_reg(host_ctxt, 3) = host_mc.nr_pages; +} + +static void handle___pkvm_hyp_reclaimable(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(enum pkvm_topup_id, id, host_ctxt, 1); + unsigned long reclaimable = 0; + + switch (id) { + case PKVM_TOPUP_HYP_ALLOC: + reclaimable = hyp_alloc_reclaimable(); + break; + default: + reclaimable = 0; + } + + cpu_reg(host_ctxt, 1) = reclaimable; +} + static void handle___tracing_load(struct kvm_cpu_context *host_ctxt) { DECLARE_REG(unsigned long, desc_hva, host_ctxt, 1); @@ -769,6 +805,8 @@ static const hcall_t host_hcall[] = { HANDLE_FUNC(__pkvm_vcpu_put), HANDLE_FUNC(__pkvm_tlb_flush_vmid), HANDLE_FUNC(__pkvm_hyp_topup), + HANDLE_FUNC(__pkvm_hyp_reclaim), + HANDLE_FUNC(__pkvm_hyp_reclaimable), }; static void handle_host_hcall(struct kvm_cpu_context *host_ctxt) diff --git a/arch/arm64/kvm/pkvm.c b/arch/arm64/kvm/pkvm.c index f5288a350069..f29134a1cc73 100644 --- a/arch/arm64/kvm/pkvm.c +++ b/arch/arm64/kvm/pkvm.c @@ -111,6 +111,30 @@ static int pkvm_hyp_topup(enum pkvm_topup_id id, unsigned long nr_pages) return res.a1; } +unsigned long pkvm_hyp_reclaim(enum pkvm_topup_id id, unsigned long target) +{ + struct kvm_hyp_memcache mc; + struct arm_smccc_res res; + unsigned long reclaimed; + + arm_smccc_1_1_hvc(KVM_HOST_SMCCC_FUNC(__pkvm_hyp_reclaim), id, target, &res); + WARN_ON(res.a0 != SMCCC_RET_SUCCESS); + if (WARN_ON_ONCE(res.a1)) + return 0; + + init_hyp_memcache(&mc); + mc.head = res.a2; + mc.nr_pages = reclaimed = res.a3; + free_hyp_memcache(&mc); + + return reclaimed; +} + +unsigned long pkvm_hyp_reclaimable(enum pkvm_topup_id id) +{ + return kvm_call_hyp_nvhe(__pkvm_hyp_reclaimable, id); +} + static int pkvm_handle_hyp_req(struct pkvm_hyp_req *req) { int ret = -EINVAL; -- 2.54.0.631.ge1b05301d1-goog