From patchwork Wed May 13 11:31:53 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Jones X-Patchwork-Id: 471818 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 5940114078C for ; Wed, 13 May 2015 21:34:26 +1000 (AEST) Received: from localhost ([::1]:48235 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YsUvg-00044u-Hj for incoming@patchwork.ozlabs.org; Wed, 13 May 2015 07:34:24 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54580) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YsUtn-00015L-U0 for qemu-devel@nongnu.org; Wed, 13 May 2015 07:32:29 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YsUth-0007XU-EY for qemu-devel@nongnu.org; Wed, 13 May 2015 07:32:27 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59884) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YsUth-0007XP-7V for qemu-devel@nongnu.org; Wed, 13 May 2015 07:32:21 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t4DBW7Dx015661 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 13 May 2015 07:32:07 -0400 Received: from localhost.localdomain.com (ovpn-204-56.brq.redhat.com [10.40.204.56]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t4DBVte8007684; Wed, 13 May 2015 07:32:04 -0400 From: Andrew Jones To: kvmarm@lists.cs.columbia.edu, qemu-devel@nongnu.org, ard.biesheuvel@linaro.org, christoffer.dall@linaro.org, marc.zyngier@arm.com, peter.maydell@linaro.org, pbonzini@redhat.com, agraf@suse.de Date: Wed, 13 May 2015 13:31:53 +0200 Message-Id: <1431516714-25816-3-git-send-email-drjones@redhat.com> In-Reply-To: <1431516714-25816-1-git-send-email-drjones@redhat.com> References: <1431516714-25816-1-git-send-email-drjones@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: catalin.marinas@arm.com, j.fanguede@virtualopensystems.com, lersek@redhat.com, m.smarduch@samsung.com Subject: [Qemu-devel] [RFC/RFT PATCH v2 2/3] KVM: promote KVM_MEMSLOT_INCOHERENT to uapi X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Commit 1050dcda30529 introduced KVM_MEMSLOT_INCOHERENT to flag memory regions that may have coherency issues due to mapping host system RAM as non-cacheable. This was introduced as a KVM internal flag, but now give KVM userspace access to it so that it may use it for hinting likely problematic regions. Also rename to KVM_MEM_UNCACHED. Signed-off-by: Andrew Jones Reviewed-by: Paolo Bonzini Reviewed-by: Christoffer Dall --- Documentation/virtual/kvm/api.txt | 20 ++++++++++++++------ arch/arm/include/uapi/asm/kvm.h | 1 + arch/arm/kvm/arm.c | 1 + arch/arm/kvm/mmu.c | 4 ++-- arch/arm64/include/uapi/asm/kvm.h | 1 + include/linux/kvm_host.h | 1 - include/uapi/linux/kvm.h | 2 ++ virt/kvm/kvm_main.c | 7 ++++++- 8 files changed, 27 insertions(+), 10 deletions(-) diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 9fa2bf8c3f6f1..04ffd9f5db5f2 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -905,6 +905,7 @@ struct kvm_userspace_memory_region { /* for kvm_memory_region::flags */ #define KVM_MEM_LOG_DIRTY_PAGES (1UL << 0) #define KVM_MEM_READONLY (1UL << 1) +#define KVM_MEM_UNCACHED (1UL << 2) This ioctl allows the user to create or modify a guest physical memory slot. When changing an existing slot, it may be moved in the guest @@ -920,12 +921,19 @@ It is recommended that the lower 21 bits of guest_phys_addr and userspace_addr be identical. This allows large pages in the guest to be backed by large pages in the host. -The flags field supports two flags: KVM_MEM_LOG_DIRTY_PAGES and -KVM_MEM_READONLY. The former can be set to instruct KVM to keep track of -writes to memory within the slot. See KVM_GET_DIRTY_LOG ioctl to know how to -use it. The latter can be set, if KVM_CAP_READONLY_MEM capability allows it, -to make a new slot read-only. In this case, writes to this memory will be -posted to userspace as KVM_EXIT_MMIO exits. +The flags field supports the following flags. All flags may be used in +combination. + - KVM_MEM_LOG_DIRTY_PAGES: no capability required + Set this to instruct KVM to keep track of writes to memory within + the slot. (See the KVM_GET_DIRTY_LOG ioctl) + - KVM_MEM_READONLY: depends on capability KVM_CAP_READONLY_MEM + Set this to make a new slot read-only. In this case, writes to + this memory will be posted to userspace as KVM_EXIT_MMIO exits. + EINVAL will be returned if the slot is not new. + - KVM_MEM_UNCACHED: depends on capability KVM_CAP_UNCACHED_MEM + Set this to make a new slot uncached, i.e. userspace will always + directly read/write RAM for this memory region. EINVAL will be + returned if the slot is not new. When the KVM_CAP_SYNC_MMU capability is available, changes in the backing of the memory region are automatically reflected into the guest. For example, an diff --git a/arch/arm/include/uapi/asm/kvm.h b/arch/arm/include/uapi/asm/kvm.h index df3f60cb1168a..893a331655115 100644 --- a/arch/arm/include/uapi/asm/kvm.h +++ b/arch/arm/include/uapi/asm/kvm.h @@ -26,6 +26,7 @@ #define __KVM_HAVE_GUEST_DEBUG #define __KVM_HAVE_IRQ_LINE #define __KVM_HAVE_READONLY_MEM +#define __KVM_HAVE_UNCACHED_MEM #define KVM_REG_SIZE(id) \ (1U << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT)) diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index d9631ecddd56e..cbb532de9c8b5 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -182,6 +182,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) case KVM_CAP_ARM_PSCI_0_2: case KVM_CAP_READONLY_MEM: case KVM_CAP_MP_STATE: + case KVM_CAP_UNCACHED_MEM: r = 1; break; case KVM_CAP_COALESCED_MMIO: diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c index 1d5accbd3dcf2..bc1665acd73e7 100644 --- a/arch/arm/kvm/mmu.c +++ b/arch/arm/kvm/mmu.c @@ -1307,7 +1307,7 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa, if (!hugetlb && !force_pte) hugetlb = transparent_hugepage_adjust(&pfn, &fault_ipa); - fault_ipa_uncached = memslot->flags & KVM_MEMSLOT_INCOHERENT; + fault_ipa_uncached = memslot->flags & KVM_MEM_UNCACHED; if (hugetlb) { pmd_t new_pmd = pfn_pmd(pfn, mem_type); @@ -1834,7 +1834,7 @@ int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot, * regions as incoherent. */ if (slot->flags & KVM_MEM_READONLY) - slot->flags |= KVM_MEMSLOT_INCOHERENT; + slot->flags |= KVM_MEM_UNCACHED; return 0; } diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h index d26832022127e..be46855ca01b7 100644 --- a/arch/arm64/include/uapi/asm/kvm.h +++ b/arch/arm64/include/uapi/asm/kvm.h @@ -38,6 +38,7 @@ #define __KVM_HAVE_GUEST_DEBUG #define __KVM_HAVE_IRQ_LINE #define __KVM_HAVE_READONLY_MEM +#define __KVM_HAVE_UNCACHED_MEM #define KVM_REG_SIZE(id) \ (1U << (((id) & KVM_REG_SIZE_MASK) >> KVM_REG_SIZE_SHIFT)) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index ad45054309a0f..74d6a14529f53 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -39,7 +39,6 @@ * include/linux/kvm_h. */ #define KVM_MEMSLOT_INVALID (1UL << 16) -#define KVM_MEMSLOT_INCOHERENT (1UL << 17) /* Two fragments for cross MMIO pages. */ #define KVM_MAX_MMIO_FRAGMENTS 2 diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h index 4b60056776d14..ceb6e805e5f77 100644 --- a/include/uapi/linux/kvm.h +++ b/include/uapi/linux/kvm.h @@ -108,6 +108,7 @@ struct kvm_userspace_memory_region { */ #define KVM_MEM_LOG_DIRTY_PAGES (1UL << 0) #define KVM_MEM_READONLY (1UL << 1) +#define KVM_MEM_UNCACHED (1UL << 2) /* for KVM_IRQ_LINE */ struct kvm_irq_level { @@ -814,6 +815,7 @@ struct kvm_ppc_smmu_info { #define KVM_CAP_S390_INJECT_IRQ 113 #define KVM_CAP_S390_IRQ_STATE 114 #define KVM_CAP_PPC_HWRNG 115 +#define KVM_CAP_UNCACHED_MEM 116 #ifdef KVM_CAP_IRQ_ROUTING diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 90977418aeb6e..d1d535d80a075 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -719,6 +719,10 @@ static int check_memory_region_flags(struct kvm_userspace_memory_region *mem) valid_flags |= KVM_MEM_READONLY; #endif +#ifdef __KVM_HAVE_UNCACHED_MEM + valid_flags |= KVM_MEM_UNCACHED; +#endif + if (mem->flags & ~valid_flags) return -EINVAL; @@ -816,7 +820,8 @@ int __kvm_set_memory_region(struct kvm *kvm, else { /* Modify an existing slot. */ if ((mem->userspace_addr != old.userspace_addr) || (npages != old.npages) || - ((new.flags ^ old.flags) & KVM_MEM_READONLY)) + ((new.flags ^ old.flags) & + (KVM_MEM_READONLY | KVM_MEM_UNCACHED))) goto out; if (base_gfn != old.base_gfn)