From: Cornelia Huck <cohuck@redhat.com> To: David Gibson <david@gibson.dropbear.id.au> Cc: qemu-devel@nongnu.org, brijesh.singh@amd.com, frankja@linux.ibm.com, dgilbert@redhat.com, pair@us.ibm.com, qemu-ppc@nongnu.org, kvm@vger.kernel.org, mdroth@linux.vnet.ibm.com, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, Paolo Bonzini <pbonzini@redhat.com>, "Michael S. Tsirkin" <mst@redhat.com>, Richard Henderson <rth@twiddle.net>, Eduardo Habkost <ehabkost@redhat.com>, Halil Pasic <pasic@linux.ibm.com> Subject: Re: [RFC v2 18/18] guest memory protection: Alter virtio default properties for protected guests Date: Fri, 5 Jun 2020 12:45:35 +0200 [thread overview] Message-ID: <20200605124535.12e8c96e.cohuck@redhat.com> (raw) In-Reply-To: <20200521034304.340040-19-david@gibson.dropbear.id.au> On Thu, 21 May 2020 13:43:04 +1000 David Gibson <david@gibson.dropbear.id.au> wrote: > 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 guest memory protection 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. cc: Halil, who had been looking at the interaction of virtio-ccw devices and s390 protected virt. (IIRC, we wanted to try with a on/off/auto property for virtio-ccw?) > > 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 88d699bceb..cb6580954e 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/guest-memory-protection.h" > +#include "hw/virtio/virtio.h" > +#include "hw/virtio/virtio-pci.h" > > GlobalProperty hw_compat_5_0[] = {}; > const size_t hw_compat_5_0_len = G_N_ELEMENTS(hw_compat_5_0); > @@ -1159,6 +1161,15 @@ 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);
WARNING: multiple messages have this Message-ID (diff)
From: Cornelia Huck <cohuck@redhat.com> To: David Gibson <david@gibson.dropbear.id.au> Cc: pair@us.ibm.com, brijesh.singh@amd.com, frankja@linux.ibm.com, kvm@vger.kernel.org, "Michael S. Tsirkin" <mst@redhat.com>, qemu-devel@nongnu.org, Eduardo Habkost <ehabkost@redhat.com>, dgilbert@redhat.com, Halil Pasic <pasic@linux.ibm.com>, qemu-ppc@nongnu.org, Paolo Bonzini <pbonzini@redhat.com>, mdroth@linux.vnet.ibm.com, Richard Henderson <rth@twiddle.net> Subject: Re: [RFC v2 18/18] guest memory protection: Alter virtio default properties for protected guests Date: Fri, 5 Jun 2020 12:45:35 +0200 [thread overview] Message-ID: <20200605124535.12e8c96e.cohuck@redhat.com> (raw) In-Reply-To: <20200521034304.340040-19-david@gibson.dropbear.id.au> On Thu, 21 May 2020 13:43:04 +1000 David Gibson <david@gibson.dropbear.id.au> wrote: > 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 guest memory protection 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. cc: Halil, who had been looking at the interaction of virtio-ccw devices and s390 protected virt. (IIRC, we wanted to try with a on/off/auto property for virtio-ccw?) > > 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 88d699bceb..cb6580954e 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/guest-memory-protection.h" > +#include "hw/virtio/virtio.h" > +#include "hw/virtio/virtio-pci.h" > > GlobalProperty hw_compat_5_0[] = {}; > const size_t hw_compat_5_0_len = G_N_ELEMENTS(hw_compat_5_0); > @@ -1159,6 +1161,15 @@ 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);
next prev parent reply other threads:[~2020-06-05 10:45 UTC|newest] Thread overview: 156+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-05-21 3:42 [RFC v2 00/18] Refactor configuration of guest memory protection David Gibson 2020-05-21 3:42 ` David Gibson 2020-05-21 3:42 ` [RFC v2 01/18] target/i386: sev: Remove unused QSevGuestInfoClass David Gibson 2020-05-21 3:42 ` David Gibson 2020-05-29 9:01 ` Philippe Mathieu-Daudé 2020-06-02 3:04 ` Richard Henderson 2020-05-21 3:42 ` [RFC v2 02/18] target/i386: sev: Move local structure definitions into .c file David Gibson 2020-05-21 3:42 ` David Gibson 2020-05-29 9:03 ` Philippe Mathieu-Daudé 2020-06-02 3:05 ` Richard Henderson 2020-05-21 3:42 ` [RFC v2 03/18] target/i386: sev: Rename QSevGuestInfo David Gibson 2020-05-21 3:42 ` David Gibson 2020-05-29 9:05 ` Philippe Mathieu-Daudé 2020-06-02 3:06 ` Richard Henderson 2020-05-21 3:42 ` [RFC v2 04/18] target/i386: sev: Embed SEVState in SevGuestState David Gibson 2020-05-21 3:42 ` David Gibson 2020-05-29 9:09 ` Philippe Mathieu-Daudé 2020-06-04 3:15 ` David Gibson 2020-06-04 3:15 ` David Gibson 2020-06-02 3:07 ` Richard Henderson 2020-05-21 3:42 ` [RFC v2 05/18] target/i386: sev: Partial cleanup to sev_state global David Gibson 2020-05-21 3:42 ` David Gibson 2020-06-02 3:08 ` Richard Henderson 2020-05-21 3:42 ` [RFC v2 06/18] target/i386: sev: Remove redundant cbitpos and reduced_phys_bits fields David Gibson 2020-05-21 3:42 ` David Gibson 2020-05-29 9:11 ` Philippe Mathieu-Daudé 2020-06-02 3:09 ` Richard Henderson 2020-05-21 3:42 ` [RFC v2 07/18] target/i386: sev: Remove redundant policy field David Gibson 2020-05-21 3:42 ` David Gibson 2020-06-02 3:13 ` Richard Henderson 2020-05-21 3:42 ` [RFC v2 08/18] target/i386: sev: Remove redundant handle field David Gibson 2020-05-21 3:42 ` David Gibson 2020-06-02 3:16 ` Richard Henderson 2020-05-21 3:42 ` [RFC v2 09/18] target/i386: sev: Unify SEVState and SevGuestState David Gibson 2020-05-21 3:42 ` David Gibson 2020-05-29 9:13 ` Philippe Mathieu-Daudé 2020-06-02 3:18 ` Richard Henderson 2020-05-21 3:42 ` [RFC v2 10/18] guest memory protection: Add guest memory protection interface David Gibson 2020-05-21 3:42 ` David Gibson 2020-05-25 10:27 ` Greg Kurz 2020-05-25 10:27 ` Greg Kurz 2020-06-03 10:09 ` David Gibson 2020-06-03 10:09 ` David Gibson 2020-06-02 1:44 ` Richard Henderson 2020-06-03 10:09 ` David Gibson 2020-06-03 10:09 ` David Gibson 2020-05-21 3:42 ` [RFC v2 11/18] guest memory protection: Handle memory encrption via interface David Gibson 2020-05-21 3:42 ` David Gibson 2020-05-25 10:26 ` Greg Kurz 2020-05-25 10:26 ` Greg Kurz 2020-06-04 3:27 ` David Gibson 2020-06-04 3:27 ` David Gibson 2020-06-02 3:21 ` Richard Henderson 2020-05-21 3:42 ` [RFC v2 12/18] guest memory protection: Perform KVM init " David Gibson 2020-05-21 3:42 ` David Gibson 2020-06-02 3:39 ` Richard Henderson 2020-06-02 3:45 ` Richard Henderson 2020-05-21 3:42 ` [RFC v2 13/18] guest memory protection: Move side effect out of machine_set_memory_encryption() David Gibson 2020-05-21 3:42 ` David Gibson 2020-06-02 3:41 ` Richard Henderson 2020-05-21 3:43 ` [RFC v2 14/18] guest memory protection: Rework the "memory-encryption" property David Gibson 2020-05-21 3:43 ` David Gibson 2020-06-02 3:54 ` Richard Henderson 2020-06-04 5:56 ` David Gibson 2020-06-04 5:56 ` David Gibson 2020-06-04 6:19 ` Thomas Huth 2020-06-04 6:19 ` Thomas Huth 2020-06-04 6:25 ` David Gibson 2020-06-04 6:25 ` David Gibson 2020-05-21 3:43 ` [RFC v2 15/18] guest memory protection: Decouple kvm_memcrypt_*() helpers from KVM David Gibson 2020-05-21 3:43 ` David Gibson 2020-06-02 4:13 ` Richard Henderson 2020-06-03 10:18 ` David Gibson 2020-06-03 10:18 ` David Gibson 2020-05-21 3:43 ` [RFC v2 16/18] guest memory protection: Add Error ** to GuestMemoryProtection::kvm_init David Gibson 2020-05-21 3:43 ` David Gibson 2020-05-29 9:16 ` Philippe Mathieu-Daudé 2020-06-02 4:15 ` Richard Henderson 2020-05-21 3:43 ` [RFC v2 17/18] spapr: Added PEF based guest memory protection David Gibson 2020-05-21 3:43 ` David Gibson 2020-05-25 11:14 ` Greg Kurz 2020-05-25 11:14 ` Greg Kurz 2020-05-29 7:59 ` Ram Pai 2020-05-29 7:59 ` Ram Pai 2020-06-04 3:46 ` David Gibson 2020-06-04 3:46 ` David Gibson 2020-05-21 3:43 ` [RFC v2 18/18] guest memory protection: Alter virtio default properties for protected guests David Gibson 2020-05-21 3:43 ` David Gibson 2020-06-05 10:45 ` Cornelia Huck [this message] 2020-06-05 10:45 ` Cornelia Huck 2020-06-05 16:04 ` Halil Pasic 2020-06-05 16:04 ` Halil Pasic 2020-06-06 20:21 ` Michael S. Tsirkin 2020-06-06 20:21 ` Michael S. Tsirkin 2020-06-07 3:07 ` David Gibson 2020-06-07 3:07 ` David Gibson 2020-06-09 10:16 ` Cornelia Huck 2020-06-09 10:16 ` Cornelia Huck 2020-06-09 15:40 ` Halil Pasic 2020-06-09 15:40 ` Halil Pasic 2020-06-09 15:57 ` Cornelia Huck 2020-06-09 15:57 ` Cornelia Huck 2020-06-09 16:01 ` Michael S. Tsirkin 2020-06-09 16:01 ` Michael S. Tsirkin 2020-06-10 4:45 ` David Gibson 2020-06-10 4:45 ` David Gibson 2020-06-10 4:39 ` David Gibson 2020-06-10 4:39 ` David Gibson 2020-06-10 8:48 ` Cornelia Huck 2020-06-10 8:48 ` Cornelia Huck 2020-06-10 10:07 ` David Gibson 2020-06-10 10:07 ` David Gibson 2020-06-10 13:21 ` Halil Pasic 2020-06-10 13:21 ` Halil Pasic 2020-05-29 22:19 ` [RFC v2 00/18] Refactor configuration of guest memory protection Sean Christopherson 2020-05-29 22:19 ` Sean Christopherson 2020-06-01 9:16 ` Dr. David Alan Gilbert 2020-06-01 9:16 ` Dr. David Alan Gilbert 2020-06-04 3:11 ` David Gibson 2020-06-04 3:11 ` David Gibson 2020-06-04 16:20 ` Sean Christopherson 2020-06-04 16:20 ` Sean Christopherson 2020-06-04 3:05 ` David Gibson 2020-06-04 3:05 ` David Gibson 2020-06-04 4:39 ` Thiago Jung Bauermann 2020-06-04 4:39 ` Thiago Jung Bauermann 2020-06-04 6:21 ` David Gibson 2020-06-04 6:21 ` David Gibson 2020-06-04 21:54 ` Thiago Jung Bauermann 2020-06-04 21:54 ` Thiago Jung Bauermann 2020-06-04 22:47 ` Paolo Bonzini 2020-06-04 22:47 ` Paolo Bonzini 2020-06-04 23:30 ` Thiago Jung Bauermann 2020-06-04 23:30 ` Thiago Jung Bauermann 2020-06-04 23:41 ` Paolo Bonzini 2020-06-04 23:41 ` Paolo Bonzini 2020-06-05 20:01 ` Thiago Jung Bauermann 2020-06-05 20:01 ` Thiago Jung Bauermann 2020-06-06 8:24 ` David Gibson 2020-06-06 8:24 ` David Gibson 2020-06-08 15:10 ` Thiago Jung Bauermann 2020-06-08 15:10 ` Thiago Jung Bauermann 2020-06-04 6:44 ` David Gibson 2020-06-04 6:44 ` David Gibson 2020-06-04 9:08 ` Greg Kurz 2020-06-04 9:08 ` Greg Kurz 2020-06-06 8:45 ` David Gibson 2020-06-06 8:45 ` David Gibson 2020-06-05 10:55 ` Cornelia Huck 2020-06-05 10:55 ` Cornelia Huck 2020-06-06 8:44 ` David Gibson 2020-06-06 8:44 ` David Gibson 2020-06-09 10:11 ` Halil Pasic 2020-06-09 10:11 ` Halil Pasic 2020-06-10 4:36 ` David Gibson 2020-06-10 4:36 ` David Gibson
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