From patchwork Fri Apr 19 08:59:23 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Bonzini X-Patchwork-Id: 13635967 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3AB637EF1D for ; Fri, 19 Apr 2024 08:59:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713517179; cv=none; b=TORFiqesQlyRy4xLurvyXiVDv8iUBclgA2YeNGixw2qrAmqcILAI1wndqYG3yBiZb/TkdVShzdF5bO7xjrEBKhfO2lynWIFsfT46QsbjUKOeySMo7mwI8On7YtkFjNjrD9HMn0cc2vjPXYuGNyodCMVjX8KjRHuiyCNPc6CqXyU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713517179; c=relaxed/simple; bh=6QsTyro7o0g/mAgLz5I9OAAjavd5uhJCINBH9wpklts=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=uPHnt7mVc02Alsze5j2hScaqOgiXYf67EJMm7L7N88QbLLwdv6Fvp6IYddcLzC2W9LyN6o7GcLCokF2u8aaA+tLY1YGIxMNcVdVjekHijtcb6V3NJviMa33Mz4gaUHtDY8sffdsNGY1hOXMUy21h8qIpc+8fuTWfi3JqYnezC4g= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=aWi/5Rol; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="aWi/5Rol" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1713517177; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=AbYCbT6M2EaJK1Q6vJ2IcYCS7NUptHbLc4XrSU4QEHw=; b=aWi/5Rolb0Bt2KfsqTRDbkL/M7uygsJz0mkZ6BRycg69Zcx26cm41nqA+QRaLxsLq0Bwp1 +HOvczo9zzqMkmrkT4AB0/tYONrqMtC6WyOgN2+rCMZ4LX2SyMiZDZXFoBljQ161MCdFlu GU94kWUkfdKmNrWFJIGxUs/3T7gkcEQ= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-265-PvhzoT8IPsW6Z41sicIZIw-1; Fri, 19 Apr 2024 04:59:30 -0400 X-MC-Unique: PvhzoT8IPsW6Z41sicIZIw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id EE12C1C294CE; Fri, 19 Apr 2024 08:59:28 +0000 (UTC) Received: from virtlab701.virt.lab.eng.bos.redhat.com (virtlab701.virt.lab.eng.bos.redhat.com [10.19.152.228]) by smtp.corp.redhat.com (Postfix) with ESMTP id BC7992033A7D; Fri, 19 Apr 2024 08:59:28 +0000 (UTC) From: Paolo Bonzini To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: isaku.yamahata@intel.com, xiaoyao.li@intel.com, binbin.wu@linux.intel.com, seanjc@google.com, rick.p.edgecombe@intel.com Subject: [PATCH 2/6] KVM: Add KVM_PRE_FAULT_MEMORY vcpu ioctl to pre-populate guest memory Date: Fri, 19 Apr 2024 04:59:23 -0400 Message-ID: <20240419085927.3648704-3-pbonzini@redhat.com> In-Reply-To: <20240419085927.3648704-1-pbonzini@redhat.com> References: <20240419085927.3648704-1-pbonzini@redhat.com> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.4 From: Isaku Yamahata Add a new ioctl KVM_PRE_FAULT_MEMORY in the KVM common code. It iterates on the memory range and calls the arch-specific function. Add stub arch function as a weak symbol. Suggested-by: Sean Christopherson Signed-off-by: Isaku Yamahata Reviewed-by: Rick Edgecombe Message-ID: <819322b8f25971f2b9933bfa4506e618508ad782.1712785629.git.isaku.yamahata@intel.com> Signed-off-by: Paolo Bonzini --- include/linux/kvm_host.h | 5 ++++ include/uapi/linux/kvm.h | 10 +++++++ virt/kvm/Kconfig | 3 ++ virt/kvm/kvm_main.c | 63 ++++++++++++++++++++++++++++++++++++++++ 4 files changed, 81 insertions(+) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 8dea11701ab2..9e9943e5e37c 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -2478,4 +2478,9 @@ long kvm_gmem_populate(struct kvm *kvm, gfn_t gfn, void __user *src, long npages void kvm_arch_gmem_invalidate(kvm_pfn_t start, kvm_pfn_t end); #endif +#ifdef CONFIG_KVM_GENERIC_PRE_FAULT_MEMORY +long kvm_arch_vcpu_pre_fault_memory(struct kvm_vcpu *vcpu, + struct kvm_pre_fault_memory *range); +#endif + #endif diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 2190adbe3002..917d2964947d 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -917,6 +917,7 @@ struct kvm_enable_cap { #define KVM_CAP_MEMORY_ATTRIBUTES 233 #define KVM_CAP_GUEST_MEMFD 234 #define KVM_CAP_VM_TYPES 235 +#define KVM_CAP_PRE_FAULT_MEMORY 236 struct kvm_irq_routing_irqchip { __u32 irqchip; @@ -1548,4 +1549,13 @@ struct kvm_create_guest_memfd { __u64 reserved[6]; }; +#define KVM_PRE_FAULT_MEMORY _IOWR(KVMIO, 0xd5, struct kvm_pre_fault_memory) + +struct kvm_pre_fault_memory { + __u64 gpa; + __u64 size; + __u64 flags; + __u64 padding[5]; +}; + #endif /* __LINUX_KVM_H */ diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig index 754c6c923427..b14e14cdbfb9 100644 --- a/virt/kvm/Kconfig +++ b/virt/kvm/Kconfig @@ -67,6 +67,9 @@ config HAVE_KVM_INVALID_WAKEUPS config KVM_GENERIC_DIRTYLOG_READ_PROTECT bool +config KVM_GENERIC_PRE_FAULT_MEMORY + bool + config KVM_COMPAT def_bool y depends on KVM && COMPAT && !(S390 || ARM64 || RISCV) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 38b498669ef9..51d8dbe7e93b 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -4379,6 +4379,55 @@ static int kvm_vcpu_ioctl_get_stats_fd(struct kvm_vcpu *vcpu) return fd; } +#ifdef CONFIG_KVM_GENERIC_PRE_FAULT_MEMORY +static int kvm_vcpu_pre_fault_memory(struct kvm_vcpu *vcpu, + struct kvm_pre_fault_memory *range) +{ + int idx; + long r; + u64 full_size; + + if (range->flags) + return -EINVAL; + + if (!PAGE_ALIGNED(range->gpa) || + !PAGE_ALIGNED(range->size) || + range->gpa + range->size <= range->gpa) + return -EINVAL; + + if (!range->size) + return 0; + + vcpu_load(vcpu); + idx = srcu_read_lock(&vcpu->kvm->srcu); + + full_size = range->size; + do { + if (signal_pending(current)) { + r = -EINTR; + break; + } + + r = kvm_arch_vcpu_pre_fault_memory(vcpu, range); + if (r < 0) + break; + + if (WARN_ON_ONCE(r == 0)) + break; + + range->size -= r; + range->gpa += r; + cond_resched(); + } while (range->size); + + srcu_read_unlock(&vcpu->kvm->srcu, idx); + vcpu_put(vcpu); + + /* Return success if at least one page was mapped successfully. */ + return full_size == range->size ? r : 0; +} +#endif + static long kvm_vcpu_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg) { @@ -4580,6 +4629,20 @@ static long kvm_vcpu_ioctl(struct file *filp, r = kvm_vcpu_ioctl_get_stats_fd(vcpu); break; } +#ifdef CONFIG_KVM_GENERIC_PRE_FAULT_MEMORY + case KVM_PRE_FAULT_MEMORY: { + struct kvm_pre_fault_memory range; + + r = -EFAULT; + if (copy_from_user(&range, argp, sizeof(range))) + break; + r = kvm_vcpu_pre_fault_memory(vcpu, &range); + /* Pass back leftover range. */ + if (copy_to_user(argp, &range, sizeof(range))) + r = -EFAULT; + break; + } +#endif default: r = kvm_arch_vcpu_ioctl(filp, ioctl, arg); }