From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f54.google.com (mail-wm1-f54.google.com [209.85.128.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 85A2B48124E for ; Wed, 15 Jul 2026 12:55:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.54 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784120132; cv=none; b=DX4H4U16Um7UNK/CnHUmWz4vpdr/uGqPa0VyXbImBhVQQzhj4Rf+Kv1Wl353tEetNpcXXvE9RVIgjqmUb3cs1ixpkEDKje2zb+1T1MYYHTs2UPp2RQbkJqrxuGlskIgUACbBTXKH4Rw6O48VsC3yuwud2Ypxa3zeLjdnCY1Vzx0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784120132; c=relaxed/simple; bh=SSZdoUwSB6ScZO9efgT73NU/st+wovAAct7MS20ttBI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=GLh8hSP7PyCIbf9AE6CCBMuKddFu3t0OM/csNhO3LfV1lY1ggVzEeXwThe2aqCS1R8fOlKSJnwaZyVxukpHV8MLCopxnRv5i2Bf1ZE/pPCg18RWmu5jaRCaDKEJv6QKqc4Dwq6PW2B12nP+bvtV7yoNwTrJMFjDbdlHcKWLN+ow= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=B/hDi9dd; arc=none smtp.client-ip=209.85.128.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="B/hDi9dd" Received: by mail-wm1-f54.google.com with SMTP id 5b1f17b1804b1-493c52cde9eso46515355e9.3 for ; Wed, 15 Jul 2026 05:55:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1784120127; x=1784724927; darn=lists.linux.dev; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=R0eO5p/+72zQTpxbfV2SGsUBVNXRFtxhqKdi0S5oNCk=; b=B/hDi9ddsJ3wTQz+fCgqiOj0yVgA/hycLEgdiXnXgr6x4Qkk5zclCtxXGh8YkkYfiP QJpwBv7mcQGFyYMHPXuH8jWlT/cyZQG328o0s5feNTMO8yqwomxi7nALLHHtmbRukBDA fcHqeeGUG/WF7ixrnE58RekeWlbORacNVXLOl026cL7JW99fQlkEvjymDYT3iphwhDqW 8/oaiFKw0KUQ2Bk1fkH78W+E+4Tjn2uhbxtVslhzkCah1NSVfwfTbUEQFZQdy2q+j27Y jYenu2NK+KilqqHEJTu/cXb+ZUDzOvloFxfJWhkaBeL+FoBAJv9fdkM1EXYE/GbsxAdx Z2qQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1784120127; x=1784724927; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=R0eO5p/+72zQTpxbfV2SGsUBVNXRFtxhqKdi0S5oNCk=; b=Y7u5yG7v7YGrwwbXjUuOrVP/HBe4O3GBd1sMD7GdbjVI9QI2e3bK0HhQ8RddRxEnel l7izpMlyIOz8ZUqe6I4xbnF5srDm6kAXYWluKyvjf6biyLKbz9PzryDXDR2v5eFND7tD lVyjuV920daKtIxlKS98Tggg4GElsjpiEjGJpd7PxxK7AohxzkjLIB3SR1qXI0QAqoUP 2idz/cxmEmaKjVuZ9ZjdcYW15yQn/POYja8DzQoCDWgD3GJDkhrakqM8rmefOCO7ujSj YGCbh6zRJB0YY6b760K9+5k0xFCngitd+Ka0PLrdw1BfXl/1RmR/kFVKbUqgwnACE5fZ 29LA== X-Forwarded-Encrypted: i=1; AHgh+RrD7p5TcUo62q/Td8SNLLKXLsKW4oRvLkEKHFe2ILcrTOxY7diK9ffkxsuREoOFikxvME2JvUs=@lists.linux.dev X-Gm-Message-State: AOJu0YyB66ey4iM8EcGwBfaZ2iMm1GUma7edTsVu9/Z7PDPEOzX6w7s8 hELr/1w3eofiSo/7YVtfy7iLqke1e+ELh4owtFE1bCA+xOm1w98RBuN0U0IvL4z3yw== X-Gm-Gg: AfdE7cmVQT+hB9DSiLHdFkjd78eJ3VsSFyoji3oUiwKkfrtglWUzNYFo9imDpmX6juN 8Q0prApMRHBmrY+S6F2JGjMEJEZQdDCuos15vcAgvMjk5SoPcppNmipuQ99sfY1Emi/b1Q2N0tj ii8tQ27JbjXZXC8BB3Y8GL6GK5qEsdCMnZN6YuQkg7247df14SHcHUr8Bk1j9CXJSOPxFZ8YMpD Bkf7NW6imRSvk2HBB7lFIIUOQdsDqvGzb/2n84+7yiW1O8ASSHgbEVMaHnvbB+PyZYp/aO4CyFT l4N2+iPJpbTi5W1SSK613gD2ej8J1b/8nZkUVdkZzCWRZ8dofBTux1tzCMhiHrqhmwYju+IbVwF Bx6BaunOjqP3Ithv6ciBZne1yNU6AlsLjzDpgj6Nw6oGrD/G+zdV4llvJEXe0AwXSVZ4qlZtunr IlA0Lxbpb+Q9uPs1W5URKE8TcpAglJH2AYEcNAmSSBObs5Lq8gqKg= X-Received: by 2002:a05:600c:524c:b0:494:df:8895 with SMTP id 5b1f17b1804b1-49538a0251emr73180985e9.24.1784120127010; Wed, 15 Jul 2026 05:55:27 -0700 (PDT) Received: from google.com (137.69.77.34.bc.googleusercontent.com. [34.77.69.137]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-47f464a9879sm17168794f8f.22.2026.07.15.05.55.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 Jul 2026 05:55:26 -0700 (PDT) Date: Wed, 15 Jul 2026 13:55:23 +0100 From: Vincent Donnefort To: Fuad Tabba Cc: 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, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, kernel-team@android.com, qperret@google.com Subject: Re: [PATCH v2 15/18] KVM: arm64: Alloc pkvm_hyp_vm using pKVM heap allocator Message-ID: References: <20260706175415.2604046-1-vdonnefort@google.com> <20260706175415.2604046-16-vdonnefort@google.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Jul 15, 2026 at 01:33:00PM +0100, Fuad Tabba wrote: > On Mon, 6 Jul 2026 at 18:54, 'Vincent Donnefort' via kernel-team > wrote: > > ... > > > --- a/arch/arm64/kvm/pkvm.c > > +++ b/arch/arm64/kvm/pkvm.c > > @@ -191,8 +191,8 @@ static int __pkvm_create_hyp_vcpu(struct kvm_vcpu *vcpu) > > */ > > static int __pkvm_create_hyp_vm(struct kvm *kvm) > > { > > - size_t pgd_sz, hyp_vm_sz; > > - void *pgd, *hyp_vm; > > + size_t pgd_sz; > > + void *pgd; > > int ret; > > > > if (kvm->created_vcpus < 1) > > @@ -209,28 +209,15 @@ static int __pkvm_create_hyp_vm(struct kvm *kvm) > > if (!pgd) > > return -ENOMEM; > > > > - /* Allocate memory to donate to hyp for vm and vcpu pointers. */ > > - hyp_vm_sz = PAGE_ALIGN(size_add(PKVM_HYP_VM_SIZE, > > - size_mul(sizeof(void *), > > - kvm->created_vcpus))); > > - hyp_vm = alloc_pages_exact(hyp_vm_sz, GFP_KERNEL_ACCOUNT); > > - if (!hyp_vm) { > > - ret = -ENOMEM; > > - goto free_pgd; > > - } > > - > > - /* Donate the VM memory to hyp and let hyp initialize it. */ > > - ret = kvm_call_hyp_nvhe(__pkvm_init_vm, kvm, hyp_vm, pgd); > > + ret = pkvm_call_hyp_req(__pkvm_init_vm, kvm, pgd); > > Sashiko might be right on the memcg point: hyp_vm used to be > GFP_KERNEL_ACCOUNT and now comes from the heap unaccounted, while pgd > next to it is still accounted, so it's inconsistent. Yep that is correct but there is no way around that: * Donated memory can now be shared be shared by several VM (or other parts of the hypervisor) * Donated memory is also not reclaimed until the shrinker fires. So we don't really have a way to account for that meta-data anymore. (I should at least mention this in the commit message) > > If we do want to fix it, would it go in pkvm_hyp_topup() to cover all > consumers rather than here? > > Cheers, > /fuad