Re: [Qemu-devel] [V6 4/4] hw/pci-host: Emulate AMD IOMMU

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Mar 03, 2016 at 12:09:28AM +0300, David Kiarie wrote:
> 
> 
> On 22/02/16 14:22, Marcel Apfelbaum wrote:
> >On 02/21/2016 08:11 PM, David Kiarie wrote:
> >>Add AMD IOMMU emulation support to q35 chipset
> >>
> >>Signed-off-by: David Kiarie <davidkiarie4@gmail.com>
> >>---
> >>  hw/pci-host/piix.c            |  1 +
> >>  hw/pci-host/q35.c             | 14 ++++++++++++--
> >>  include/hw/i386/intel_iommu.h |  1 +
> >>  3 files changed, 14 insertions(+), 2 deletions(-)
> >>
> >>diff --git a/hw/pci-host/piix.c b/hw/pci-host/piix.c
> >>index 41aa66f..ab2e24a 100644
> >>--- a/hw/pci-host/piix.c
> >>+++ b/hw/pci-host/piix.c
> >>@@ -36,6 +36,7 @@
> >>  #include "hw/i386/ioapic.h"
> >>  #include "qapi/visitor.h"
> >>  #include "qemu/error-report.h"
> >>+#include "hw/i386/amd_iommu.h"
> >
> >Hi,
> >
> >I think you don't need this include anymore.
> >
> >>
> >>  /*
> >>   * I440FX chipset data sheet.
> >>diff --git a/hw/pci-host/q35.c b/hw/pci-host/q35.c
> >>index 115fb8c..355fb32 100644
> >>--- a/hw/pci-host/q35.c
> >>+++ b/hw/pci-host/q35.c
> >>@@ -31,6 +31,7 @@
> >>  #include "hw/hw.h"
> >>  #include "hw/pci-host/q35.h"
> >>  #include "qapi/visitor.h"
> >>+#include "hw/i386/amd_iommu.h"
> >>
> >>/****************************************************************************
> >>   * Q35 host
> >>@@ -505,9 +506,18 @@ static void mch_realize(PCIDevice *d, Error **errp)
> >>                   mch->pci_address_space, &mch->pam_regions[i+1],
> >>                   PAM_EXPAN_BASE + i * PAM_EXPAN_SIZE, PAM_EXPAN_SIZE);
> >>      }
> >>-    /* Intel IOMMU (VT-d) */
> >>-    if (object_property_get_bool(qdev_get_machine(), "iommu", NULL)) {
> >>+
> >>+    if (g_strcmp0(MACHINE(qdev_get_machine())->iommu, INTEL_IOMMU_STR)
> >>== 0) {
> >>+        /* Intel IOMMU (VT-d) */
> >>          mch_init_dmar(mch);
> >>+    } else if (g_strcmp0(MACHINE(qdev_get_machine())->iommu,
> >>AMD_IOMMU_STR)
> >>+               == 0) {
> >>+        AMDIOMMUState *iommu_state;
> >>+        PCIDevice *iommu;
> >>+        PCIBus *bus = PCI_BUS(qdev_get_parent_bus(DEVICE(mch)));
> >>+        iommu = pci_create_simple(bus, 0x20, TYPE_AMD_IOMMU_DEVICE);

Pls don't hardcode paths like this. Set addr property instead.

> >>+        iommu_state = AMD_IOMMU_DEVICE(iommu);
> >>+        pci_setup_iommu(bus, bridge_host_amd_iommu, iommu_state);
> >
> >pci_setup_iommu third parameter is void*, so you don't need to cast to
> >AMDIOMMUState
> >before passing it.
> 
> This include is necessary for the definition of "AMD_IOMMU_STR" either way
> so am leaving this as is.

This option parsing is just too ugly.

Looks like it was a mistake to support the iommu
machine property, but I see no reason to add to the
existing mess.

Can't users create iommu with -device amd-iommu ?

It's necessary if we are to support multiple IOMMUs, anyway.

> >
> >Thanks,
> >Marcel
> >
> >>      }
> >>  }
> >>
> >>diff --git a/include/hw/i386/intel_iommu.h
> >>b/include/hw/i386/intel_iommu.h
> >>index b024ffa..539530c 100644
> >>--- a/include/hw/i386/intel_iommu.h
> >>+++ b/include/hw/i386/intel_iommu.h
> >>@@ -27,6 +27,7 @@
> >>  #define TYPE_INTEL_IOMMU_DEVICE "intel-iommu"
> >>  #define INTEL_IOMMU_DEVICE(obj) \
> >>       OBJECT_CHECK(IntelIOMMUState, (obj), TYPE_INTEL_IOMMU_DEVICE)
> >>+#define INTEL_IOMMU_STR "intel"
> >>
> >>  /* DMAR Hardware Unit Definition address (IOMMU unit) */
> >>  #define Q35_HOST_BRIDGE_IOMMU_ADDR  0xfed90000ULL
> >>
> >