From: David Gibson <david@gibson.dropbear.id.au> To: qemu-devel@nongnu.org, brijesh.singh@amd.com, pair@us.ibm.com, pbonzini@redhat.com, dgilbert@redhat.com, frankja@linux.ibm.com Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, kvm@vger.kernel.org, qemu-ppc@nongnu.org, mst@redhat.com, mdroth@linux.vnet.ibm.com, Richard Henderson <rth@twiddle.net>, cohuck@redhat.com, pasic@linux.ibm.com, Eduardo Habkost <ehabkost@redhat.com>, David Gibson <david@gibson.dropbear.id.au>, qemu-s390x@nongnu.org, david@redhat.com Subject: [PATCH v3 9/9] host trust limitation: Alter virtio default properties for protected guests Date: Fri, 19 Jun 2020 12:06:02 +1000 [thread overview] Message-ID: <20200619020602.118306-10-david@gibson.dropbear.id.au> (raw) In-Reply-To: <20200619020602.118306-1-david@gibson.dropbear.id.au> The default behaviour for virtio devices is not to use the platforms normal DMA paths, but instead to use the fact that it's running in a hypervisor to directly access guest memory. That doesn't work if the guest's memory is protected from hypervisor access, such as with AMD's SEV or POWER's PEF. So, if a host trust limitation mechanism is enabled, then apply the iommu_platform=on option so it will go through normal DMA mechanisms. Those will presumably have some way of marking memory as shared with the hypervisor or hardware so that DMA will work. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> --- hw/core/machine.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/hw/core/machine.c b/hw/core/machine.c index a71792bc16..8dfc1bb3f8 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -28,6 +28,8 @@ #include "hw/mem/nvdimm.h" #include "migration/vmstate.h" #include "exec/host-trust-limitation.h" +#include "hw/virtio/virtio.h" +#include "hw/virtio/virtio-pci.h" GlobalProperty hw_compat_5_0[] = { { "virtio-balloon-device", "page-poison", "false" }, @@ -1165,6 +1167,15 @@ void machine_run_board_init(MachineState *machine) * areas. */ machine_set_mem_merge(OBJECT(machine), false, &error_abort); + + /* + * Virtio devices can't count on directly accessing guest + * memory, so they need iommu_platform=on to use normal DMA + * mechanisms. That requires disabling legacy virtio support + * for virtio pci devices + */ + object_register_sugar_prop(TYPE_VIRTIO_PCI, "disable-legacy", "on"); + object_register_sugar_prop(TYPE_VIRTIO_DEVICE, "iommu_platform", "on"); } machine_class->init(machine); -- 2.26.2
WARNING: multiple messages have this Message-ID (diff)
From: David Gibson <david@gibson.dropbear.id.au> To: qemu-devel@nongnu.org, brijesh.singh@amd.com, pair@us.ibm.com, pbonzini@redhat.com, dgilbert@redhat.com, frankja@linux.ibm.com Cc: Eduardo Habkost <ehabkost@redhat.com>, kvm@vger.kernel.org, mst@redhat.com, cohuck@redhat.com, david@redhat.com, mdroth@linux.vnet.ibm.com, pasic@linux.ibm.com, qemu-s390x@nongnu.org, qemu-ppc@nongnu.org, David Gibson <david@gibson.dropbear.id.au>, Richard Henderson <rth@twiddle.net> Subject: [PATCH v3 9/9] host trust limitation: Alter virtio default properties for protected guests Date: Fri, 19 Jun 2020 12:06:02 +1000 [thread overview] Message-ID: <20200619020602.118306-10-david@gibson.dropbear.id.au> (raw) In-Reply-To: <20200619020602.118306-1-david@gibson.dropbear.id.au> The default behaviour for virtio devices is not to use the platforms normal DMA paths, but instead to use the fact that it's running in a hypervisor to directly access guest memory. That doesn't work if the guest's memory is protected from hypervisor access, such as with AMD's SEV or POWER's PEF. So, if a host trust limitation mechanism is enabled, then apply the iommu_platform=on option so it will go through normal DMA mechanisms. Those will presumably have some way of marking memory as shared with the hypervisor or hardware so that DMA will work. Signed-off-by: David Gibson <david@gibson.dropbear.id.au> --- hw/core/machine.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/hw/core/machine.c b/hw/core/machine.c index a71792bc16..8dfc1bb3f8 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -28,6 +28,8 @@ #include "hw/mem/nvdimm.h" #include "migration/vmstate.h" #include "exec/host-trust-limitation.h" +#include "hw/virtio/virtio.h" +#include "hw/virtio/virtio-pci.h" GlobalProperty hw_compat_5_0[] = { { "virtio-balloon-device", "page-poison", "false" }, @@ -1165,6 +1167,15 @@ void machine_run_board_init(MachineState *machine) * areas. */ machine_set_mem_merge(OBJECT(machine), false, &error_abort); + + /* + * Virtio devices can't count on directly accessing guest + * memory, so they need iommu_platform=on to use normal DMA + * mechanisms. That requires disabling legacy virtio support + * for virtio pci devices + */ + object_register_sugar_prop(TYPE_VIRTIO_PCI, "disable-legacy", "on"); + object_register_sugar_prop(TYPE_VIRTIO_DEVICE, "iommu_platform", "on"); } machine_class->init(machine); -- 2.26.2
next prev parent reply other threads:[~2020-06-19 2:06 UTC|newest] Thread overview: 112+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-06-19 2:05 [PATCH v3 0/9] Generalize memory encryption models David Gibson 2020-06-19 2:05 ` David Gibson 2020-06-19 2:05 ` [PATCH v3 1/9] host trust limitation: Introduce new host trust limitation interface David Gibson 2020-06-19 2:05 ` David Gibson 2020-06-26 11:01 ` Dr. David Alan Gilbert 2020-06-26 11:01 ` Dr. David Alan Gilbert 2020-07-14 19:26 ` Richard Henderson 2020-07-14 19:26 ` Richard Henderson 2020-06-19 2:05 ` [PATCH v3 2/9] host trust limitation: Handle memory encryption via interface David Gibson 2020-06-19 2:05 ` David Gibson 2020-06-19 2:05 ` [PATCH v3 3/9] host trust limitation: Move side effect out of machine_set_memory_encryption() David Gibson 2020-06-19 2:05 ` David Gibson 2020-06-19 2:05 ` [PATCH v3 4/9] host trust limitation: Rework the "memory-encryption" property David Gibson 2020-06-19 2:05 ` David Gibson 2020-07-14 19:36 ` Richard Henderson 2020-07-14 19:36 ` Richard Henderson 2020-06-19 2:05 ` [PATCH v3 5/9] host trust limitation: Decouple kvm_memcrypt_*() helpers from KVM David Gibson 2020-06-19 2:05 ` David Gibson 2020-06-19 2:05 ` [PATCH v3 6/9] host trust limitation: Add Error ** to HostTrustLimitation::kvm_init David Gibson 2020-06-19 2:05 ` David Gibson 2020-06-19 2:06 ` [PATCH v3 7/9] spapr: Add PEF based host trust limitation David Gibson 2020-06-19 2:06 ` David Gibson 2020-06-19 2:06 ` [PATCH v3 8/9] spapr: PEF: block migration David Gibson 2020-06-19 2:06 ` David Gibson 2020-06-26 10:33 ` Dr. David Alan Gilbert 2020-06-26 10:33 ` Dr. David Alan Gilbert 2020-07-05 7:38 ` David Gibson 2020-07-05 7:38 ` David Gibson 2020-06-19 2:06 ` David Gibson [this message] 2020-06-19 2:06 ` [PATCH v3 9/9] host trust limitation: Alter virtio default properties for protected guests David Gibson 2020-06-19 10:12 ` Daniel P. Berrangé 2020-06-19 10:12 ` Daniel P. Berrangé 2020-06-19 11:46 ` Michael S. Tsirkin 2020-06-19 11:46 ` Michael S. Tsirkin 2020-06-19 11:47 ` Michael S. Tsirkin 2020-06-19 11:47 ` Michael S. Tsirkin 2020-06-19 12:16 ` Daniel P. Berrangé 2020-06-19 12:16 ` Daniel P. Berrangé 2020-06-19 20:04 ` Halil Pasic 2020-06-19 20:04 ` Halil Pasic 2020-06-24 7:55 ` Michael S. Tsirkin 2020-06-24 7:55 ` Michael S. Tsirkin 2020-06-25 4:57 ` David Gibson 2020-06-25 4:57 ` David Gibson 2020-06-25 5:02 ` David Gibson 2020-06-25 5:02 ` David Gibson 2020-06-19 14:45 ` David Gibson 2020-06-19 14:45 ` David Gibson 2020-06-19 15:05 ` Daniel P. Berrangé 2020-06-19 15:05 ` Daniel P. Berrangé 2020-06-20 8:24 ` David Gibson 2020-06-20 8:24 ` David Gibson 2020-06-22 9:09 ` Daniel P. Berrangé 2020-06-22 9:09 ` Daniel P. Berrangé 2020-06-25 5:06 ` David Gibson 2020-06-25 5:06 ` David Gibson 2020-06-19 2:42 ` [PATCH v3 0/9] Generalize memory encryption models no-reply 2020-06-19 2:42 ` no-reply 2020-06-19 8:28 ` David Hildenbrand 2020-06-19 8:28 ` David Hildenbrand 2020-06-19 9:45 ` Cornelia Huck 2020-06-19 9:45 ` Cornelia Huck 2020-06-19 9:56 ` David Hildenbrand 2020-06-19 9:56 ` David Hildenbrand 2020-06-19 10:05 ` Cornelia Huck 2020-06-19 10:05 ` Cornelia Huck 2020-06-19 10:10 ` David Hildenbrand 2020-06-19 10:10 ` David Hildenbrand 2020-06-22 12:02 ` Cornelia Huck 2020-06-22 12:02 ` Cornelia Huck 2020-06-25 5:25 ` David Gibson 2020-06-25 5:25 ` David Gibson 2020-06-25 7:06 ` David Hildenbrand 2020-06-25 7:06 ` David Hildenbrand 2020-06-26 4:42 ` David Gibson 2020-06-26 4:42 ` David Gibson 2020-06-26 6:53 ` David Hildenbrand 2020-06-26 6:53 ` David Hildenbrand 2020-06-26 9:01 ` Janosch Frank 2020-06-26 9:01 ` Janosch Frank 2020-06-26 9:32 ` Daniel P. Berrangé 2020-06-26 9:32 ` Daniel P. Berrangé 2020-06-26 9:49 ` Janosch Frank 2020-06-26 9:49 ` Janosch Frank 2020-06-26 10:29 ` Dr. David Alan Gilbert 2020-06-26 10:29 ` Dr. David Alan Gilbert 2020-06-26 10:58 ` Daniel P. Berrangé 2020-06-26 10:58 ` Daniel P. Berrangé 2020-06-26 12:49 ` Janosch Frank 2020-06-26 12:49 ` Janosch Frank 2020-07-01 11:59 ` Halil Pasic 2020-07-01 11:59 ` Halil Pasic 2020-06-19 9:48 ` David Gibson 2020-06-19 9:48 ` David Gibson 2020-06-19 10:04 ` David Hildenbrand 2020-06-19 10:04 ` David Hildenbrand 2020-06-25 5:42 ` David Gibson 2020-06-25 5:42 ` David Gibson 2020-06-25 6:59 ` David Hildenbrand 2020-06-25 6:59 ` David Hildenbrand 2020-06-25 9:49 ` Cornelia Huck 2020-06-25 9:49 ` Cornelia Huck 2020-06-22 14:27 ` Christian Borntraeger 2020-06-22 14:27 ` Christian Borntraeger 2020-06-24 7:06 ` Cornelia Huck 2020-06-24 7:06 ` Cornelia Huck 2020-06-25 5:47 ` David Gibson 2020-06-25 5:47 ` David Gibson 2020-06-25 5:48 ` David Gibson 2020-06-25 5:48 ` David Gibson 2020-06-25 5:44 ` David Gibson 2020-06-25 5:44 ` David Gibson
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