From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qt1-f175.google.com (mail-qt1-f175.google.com [209.85.160.175]) (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 EC018175A5 for ; Wed, 4 Jun 2025 13:31:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.175 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749043911; cv=none; b=c4R+JzOvm1hVVUBKB3xUwOgdYxFMwjxPEsHRBnCaxdNT3c+jjE9xUADn5M4T1Thyl7boK+7rESh4sejPEl9fn5DM5yXydBwKQg6KAQgCtkD8IYVmkzzK5z/WCQlYnru9JaXWer9pWRQ8IpwBcgpKKnCtMgX4vZlXIwdbux1VDco= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749043911; c=relaxed/simple; bh=O+3qYBkuZvOYKdQmd+lqFDADiWY3hm2oALBY8YyGjRA=; h=MIME-Version:References:In-Reply-To:From:Date:Message-ID:Subject: To:Cc:Content-Type; b=SZj3j4JJ4FMyPwHyiZxLXf2olpvXX8LdHfHdpQTA1TulkO6XOYRpIAjxangdxYpWgZz7C5cTGh25Yc/yCPJSKq3r/RSnWh+bge8LR3d++n2ACqYulvunldo9QUmS7aPhHlc11zC45+22QlFa6aAYX0dUMZrgAAIVtCRnaiaj3Bs= 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=M6TjxX+2; arc=none smtp.client-ip=209.85.160.175 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="M6TjxX+2" Received: by mail-qt1-f175.google.com with SMTP id d75a77b69052e-4a58197794eso220991cf.1 for ; Wed, 04 Jun 2025 06:31:49 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1749043909; x=1749648709; darn=vger.kernel.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=U64ULQY366JHJ6Sx1aslM0i3znI6AoNF+AhIqQiQaNw=; b=M6TjxX+2mKoMXbSK37pkS0oYYSa+u5VD8AxDLuxkiT2xn2AZwDEpVZv0pwbW3RcOcg HmtqbxIyW8aFWU0vUSugUEeHvouiJMDwuNnzWaHlbJicSxpcQ7s9J+kDFpFwSUj6A8TH /JyzDqt5C9udJWvewUiSSQIfcVoyLYbcm+LA9cGOrWRwNBqyqcFQYl1LsDX2FLmP12Es Mfu8kQccJZiXUcBCmz16uwbV+ARj9xEL3awk2j5eMN6vE0uSgNXPF3KT7HC40U4wEt1/ GI2TUj5Eg7GsrybHVm3QSYkMGbyjrF2F4jO9gHxeuSmDcDtE4QAm9OBuQL7o3kg/qO3Q R6GA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1749043909; x=1749648709; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=U64ULQY366JHJ6Sx1aslM0i3znI6AoNF+AhIqQiQaNw=; b=SkunTdoYkPsJ+8nFrMDwC3KvFNREslRZKEhHpI/HCUbVdv1G+WGJcpOnM8F0kNdX/W OEBz05t5w6Nx7T8x9hfX1BfnPusqFzAXZjVU5807tIJzVMfEIJGWZ4rIeICGS+ZOySQD vYCc5N8U9aBsg6bvaMo9JWDX+dQat2iaU8sADdMuRpEcv6LA+Sd88gA/pe6x3QX74VsT Vt+qXuJFNDMA1AynRp6h4Aac4hY+NCukuja1kcs3A6G7Uc1O5e3q5w9wt3OGVDcYwWTw 9QJWqXbkogPjdqEB82saIR+etTi+v3oDZk+YI3BWLbPAzzJGDFe28u0UG+hjIX69MyQl dBRw== X-Gm-Message-State: AOJu0Yxe6g5CvKJRJNcLzv2WnmR444CiCdAo/tmHUuudFA6bnOjxDVi/ azFj5k5owYXrN9WafFNdbPlNe6OuMKhpow0I6tbUboIpvcnsu6eQ9FdJGZ1WJVcCoD5yI9Qj/UC o3W7orchZtNbjMqyywD4fRr4y13M01kTjkDaHPvNP X-Gm-Gg: ASbGncsJtCJ5VrB/54esGrru23gqa6JnjjQ/otzOwk7DEJlAm45uBRbRDVlCQBN93lZ hHrGkt5o8SfQtqT4bMV6JtzKeObCiWK3vUqogIyk7aetRExQRvxEKDc+XaJ4KaAZOASuvvO4hpF 6xFlsGFPX/5767GfsBgwtpjM6xnQivH0ZJIlXeWiAzP5dAOshiwY/USY5tyv/WViCwOTcEuXc= X-Google-Smtp-Source: AGHT+IHFxNyfeCkrmPB39UOxojEdJAvr9WP0K1kR8JJNwFVpZqhXOBdLWxdCHfxLQMAur6bywA3oSFCMPjvNqDTSLOA= X-Received: by 2002:a05:622a:5912:b0:48a:5b89:473b with SMTP id d75a77b69052e-4a5a60dcaf0mr3295721cf.7.1749043908478; Wed, 04 Jun 2025 06:31:48 -0700 (PDT) Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20250527180245.1413463-1-tabba@google.com> <20250527180245.1413463-15-tabba@google.com> <2195c01b-3a17-46c5-a013-66922e8509bd@redhat.com> In-Reply-To: <2195c01b-3a17-46c5-a013-66922e8509bd@redhat.com> From: Fuad Tabba Date: Wed, 4 Jun 2025 14:31:11 +0100 X-Gm-Features: AX0GCFtqukMxO0pis2hyEa-S596-RXzEqFLluLmu-N319w02tyWHzt3chjxqO1k Message-ID: Subject: Re: [PATCH v10 14/16] KVM: arm64: Enable mapping guest_memfd in arm64 To: David Hildenbrand Cc: kvm@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-mm@kvack.org, pbonzini@redhat.com, chenhuacai@kernel.org, mpe@ellerman.id.au, anup@brainfault.org, paul.walmsley@sifive.com, palmer@dabbelt.com, aou@eecs.berkeley.edu, seanjc@google.com, viro@zeniv.linux.org.uk, brauner@kernel.org, willy@infradead.org, akpm@linux-foundation.org, xiaoyao.li@intel.com, yilun.xu@intel.com, chao.p.peng@linux.intel.com, jarkko@kernel.org, amoorthy@google.com, dmatlack@google.com, isaku.yamahata@intel.com, mic@digikod.net, vbabka@suse.cz, vannapurve@google.com, ackerleytng@google.com, mail@maciej.szmigiero.name, michael.roth@amd.com, wei.w.wang@intel.com, liam.merwick@oracle.com, isaku.yamahata@gmail.com, kirill.shutemov@linux.intel.com, suzuki.poulose@arm.com, steven.price@arm.com, quic_eberman@quicinc.com, quic_mnalajal@quicinc.com, quic_tsoni@quicinc.com, quic_svaddagi@quicinc.com, quic_cvanscha@quicinc.com, quic_pderrin@quicinc.com, quic_pheragu@quicinc.com, catalin.marinas@arm.com, james.morse@arm.com, yuzenghui@huawei.com, oliver.upton@linux.dev, maz@kernel.org, will@kernel.org, qperret@google.com, keirf@google.com, roypat@amazon.co.uk, shuah@kernel.org, hch@infradead.org, jgg@nvidia.com, rientjes@google.com, jhubbard@nvidia.com, fvdl@google.com, hughd@google.com, jthoughton@google.com, peterx@redhat.com, pankaj.gupta@amd.com, ira.weiny@intel.com Content-Type: text/plain; charset="UTF-8" On Wed, 4 Jun 2025 at 14:17, David Hildenbrand wrote: > > On 27.05.25 20:02, Fuad Tabba wrote: > > Enable mapping guest_memfd backed memory at the host in arm64. For now, > > it applies to all arm64 VM types in arm64 that use guest_memfd. In the > > future, new VM types can restrict this via > > kvm_arch_gmem_supports_shared_mem(). > > > > Signed-off-by: Fuad Tabba > > --- > > arch/arm64/include/asm/kvm_host.h | 5 +++++ > > arch/arm64/kvm/Kconfig | 1 + > > arch/arm64/kvm/mmu.c | 7 +++++++ > > 3 files changed, 13 insertions(+) > > > > diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h > > index 08ba91e6fb03..8add94929711 100644 > > --- a/arch/arm64/include/asm/kvm_host.h > > +++ b/arch/arm64/include/asm/kvm_host.h > > @@ -1593,4 +1593,9 @@ static inline bool kvm_arch_has_irq_bypass(void) > > return true; > > } > > > > +#ifdef CONFIG_KVM_GMEM > > +#define kvm_arch_supports_gmem(kvm) true > > +#define kvm_arch_supports_gmem_shared_mem(kvm) IS_ENABLED(CONFIG_KVM_GMEM_SHARED_MEM) > > +#endif > > + > > #endif /* __ARM64_KVM_HOST_H__ */ > > diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig > > index 096e45acadb2..8c1e1964b46a 100644 > > --- a/arch/arm64/kvm/Kconfig > > +++ b/arch/arm64/kvm/Kconfig > > @@ -38,6 +38,7 @@ menuconfig KVM > > select HAVE_KVM_VCPU_RUN_PID_CHANGE > > select SCHED_INFO > > select GUEST_PERF_EVENTS if PERF_EVENTS > > + select KVM_GMEM_SHARED_MEM > > help > > Support hosting virtualized guest machines. > > > > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c > > index 896c56683d88..03da08390bf0 100644 > > --- a/arch/arm64/kvm/mmu.c > > +++ b/arch/arm64/kvm/mmu.c > > @@ -2264,6 +2264,13 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, > > if ((new->base_gfn + new->npages) > (kvm_phys_size(&kvm->arch.mmu) >> PAGE_SHIFT)) > > return -EFAULT; > > > > + /* > > + * Only support guest_memfd backed memslots with shared memory, since > > + * there aren't any CoCo VMs that support only private memory on arm64. > > + */ > > + if (kvm_slot_has_gmem(new) && !kvm_gmem_memslot_supports_shared(new)) > > + return -EINVAL; > > + > > Right, that can get lifted once we have such VMs. > > Acked-by: David Hildenbrand Thanks! /fuad > -- > Cheers, > > David / dhildenb >