This patch adds set/unset_iommu_context() impelementation in Intel
vIOMMU. For Intel platform, pass-through modules (e.g. VFIO) could
set HostIOMMUContext to Intel vIOMMU emulator.
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Yi Sun <yi.y.sun@linux.intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
---
hw/i386/intel_iommu.c | 71 ++++++++++++++++++++++++++++++++++++++++---
include/hw/i386/intel_iommu.h | 21 ++++++++++---
2 files changed, 83 insertions(+), 9 deletions(-)
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 4b22910..fd349c6 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -3354,23 +3354,33 @@ static const MemoryRegionOps vtd_mem_ir_ops = {
},
};
-VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn)
+/**
+ * Fetch a VTDBus instance for given PCIBus. If no existing instance,
+ * allocate one.
+ */
+static VTDBus *vtd_find_add_bus(IntelIOMMUState *s, PCIBus *bus)
{
uintptr_t key = (uintptr_t)bus;
VTDBus *vtd_bus = g_hash_table_lookup(s->vtd_as_by_busptr, &key);
- VTDAddressSpace *vtd_dev_as;
- char name[128];
if (!vtd_bus) {
uintptr_t *new_key = g_malloc(sizeof(*new_key));
*new_key = (uintptr_t)bus;
/* No corresponding free() */
- vtd_bus = g_malloc0(sizeof(VTDBus) + sizeof(VTDAddressSpace *) * \
- PCI_DEVFN_MAX);
+ vtd_bus = g_malloc0(sizeof(VTDBus));
vtd_bus->bus = bus;
g_hash_table_insert(s->vtd_as_by_busptr, new_key, vtd_bus);
}
+ return vtd_bus;
+}
+VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn)
+{
+ VTDBus *vtd_bus;
+ VTDAddressSpace *vtd_dev_as;
+ char name[128];
+
+ vtd_bus = vtd_find_add_bus(s, bus);
vtd_dev_as = vtd_bus->dev_as[devfn];
if (!vtd_dev_as) {
@@ -3436,6 +3446,55 @@ VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn)
return vtd_dev_as;
}
+static int vtd_dev_set_iommu_context(PCIBus *bus, void *opaque,
+ int devfn,
+ HostIOMMUContext *iommu_ctx)
+{
+ IntelIOMMUState *s = opaque;
+ VTDBus *vtd_bus;
+ VTDHostIOMMUContext *vtd_dev_icx;
+
+ assert(0 <= devfn && devfn < PCI_DEVFN_MAX);
+
+ vtd_bus = vtd_find_add_bus(s, bus);
+
+ vtd_iommu_lock(s);
+
+ vtd_dev_icx = vtd_bus->dev_icx[devfn];
+
+ assert(!vtd_dev_icx);
+
+ vtd_bus->dev_icx[devfn] = vtd_dev_icx =
+ g_malloc0(sizeof(VTDHostIOMMUContext));
+ vtd_dev_icx->vtd_bus = vtd_bus;
+ vtd_dev_icx->devfn = (uint8_t)devfn;
+ vtd_dev_icx->iommu_state = s;
+ vtd_dev_icx->iommu_ctx = iommu_ctx;
+
+ vtd_iommu_unlock(s);
+
+ return 0;
+}
+
+static void vtd_dev_unset_iommu_context(PCIBus *bus, void *opaque, int devfn)
+{
+ IntelIOMMUState *s = opaque;
+ VTDBus *vtd_bus;
+ VTDHostIOMMUContext *vtd_dev_icx;
+
+ assert(0 <= devfn && devfn < PCI_DEVFN_MAX);
+
+ vtd_bus = vtd_find_add_bus(s, bus);
+
+ vtd_iommu_lock(s);
+
+ vtd_dev_icx = vtd_bus->dev_icx[devfn];
+ g_free(vtd_dev_icx);
+ vtd_bus->dev_icx[devfn] = NULL;
+
+ vtd_iommu_unlock(s);
+}
+
static uint64_t get_naturally_aligned_size(uint64_t start,
uint64_t size, int gaw)
{
@@ -3731,6 +3790,8 @@ static AddressSpace *vtd_host_dma_iommu(PCIBus *bus, void *opaque, int devfn)
static PCIIOMMUOps vtd_iommu_ops = {
.get_address_space = vtd_host_dma_iommu,
+ .set_iommu_context = vtd_dev_set_iommu_context,
+ .unset_iommu_context = vtd_dev_unset_iommu_context,
};
static bool vtd_decide_config(IntelIOMMUState *s, Error **errp)
diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
index 3870052..b5fefb9 100644
--- a/include/hw/i386/intel_iommu.h
+++ b/include/hw/i386/intel_iommu.h
@@ -64,6 +64,7 @@ typedef union VTD_IR_TableEntry VTD_IR_TableEntry;
typedef union VTD_IR_MSIAddress VTD_IR_MSIAddress;
typedef struct VTDPASIDDirEntry VTDPASIDDirEntry;
typedef struct VTDPASIDEntry VTDPASIDEntry;
+typedef struct VTDHostIOMMUContext VTDHostIOMMUContext;
/* Context-Entry */
struct VTDContextEntry {
@@ -112,10 +113,20 @@ struct VTDAddressSpace {
IOVATree *iova_tree; /* Traces mapped IOVA ranges */
};
+struct VTDHostIOMMUContext {
+ VTDBus *vtd_bus;
+ uint8_t devfn;
+ HostIOMMUContext *iommu_ctx;
+ IntelIOMMUState *iommu_state;
+};
+
struct VTDBus {
- PCIBus* bus; /* A reference to the bus to provide translation for */
+ /* A reference to the bus to provide translation for */
+ PCIBus *bus;
/* A table of VTDAddressSpace objects indexed by devfn */
- VTDAddressSpace *dev_as[];
+ VTDAddressSpace *dev_as[PCI_DEVFN_MAX];
+ /* A table of VTDHostIOMMUContext objects indexed by devfn */
+ VTDHostIOMMUContext *dev_icx[PCI_DEVFN_MAX];
};
struct VTDIOTLBEntry {
@@ -269,8 +280,10 @@ struct IntelIOMMUState {
bool dma_drain; /* Whether DMA r/w draining enabled */
/*
- * Protects IOMMU states in general. Currently it protects the
- * per-IOMMU IOTLB cache, and context entry cache in VTDAddressSpace.
+ * iommu_lock protects below:
+ * - per-IOMMU IOTLB caches
+ * - context entry cache in VTDAddressSpace
+ * - HostIOMMUContext pointer cached in vIOMMU
*/
QemuMutex iommu_lock;
};
--
2.7.4
Yi,
On 3/30/20 6:24 AM, Liu Yi L wrote:
> This patch adds set/unset_iommu_context() impelementation in Intel
This patch implements the set/unset_iommu_context() ops for Intel vIOMMU.
> vIOMMU. For Intel platform, pass-through modules (e.g. VFIO) could
> set HostIOMMUContext to Intel vIOMMU emulator.
>
> Cc: Kevin Tian <kevin.tian@intel.com>
> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
> Cc: Peter Xu <peterx@redhat.com>
> Cc: Yi Sun <yi.y.sun@linux.intel.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Cc: Richard Henderson <rth@twiddle.net>
> Cc: Eduardo Habkost <ehabkost@redhat.com>
> Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
> ---
> hw/i386/intel_iommu.c | 71 ++++++++++++++++++++++++++++++++++++++++---
> include/hw/i386/intel_iommu.h | 21 ++++++++++---
> 2 files changed, 83 insertions(+), 9 deletions(-)
>
> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> index 4b22910..fd349c6 100644
> --- a/hw/i386/intel_iommu.c
> +++ b/hw/i386/intel_iommu.c
> @@ -3354,23 +3354,33 @@ static const MemoryRegionOps vtd_mem_ir_ops = {
> },
> };
>
> -VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn)
> +/**
> + * Fetch a VTDBus instance for given PCIBus. If no existing instance,
> + * allocate one.
> + */
> +static VTDBus *vtd_find_add_bus(IntelIOMMUState *s, PCIBus *bus)
> {
> uintptr_t key = (uintptr_t)bus;
> VTDBus *vtd_bus = g_hash_table_lookup(s->vtd_as_by_busptr, &key);
> - VTDAddressSpace *vtd_dev_as;
> - char name[128];
>
> if (!vtd_bus) {
> uintptr_t *new_key = g_malloc(sizeof(*new_key));
> *new_key = (uintptr_t)bus;
> /* No corresponding free() */
> - vtd_bus = g_malloc0(sizeof(VTDBus) + sizeof(VTDAddressSpace *) * \
> - PCI_DEVFN_MAX);
> + vtd_bus = g_malloc0(sizeof(VTDBus));
> vtd_bus->bus = bus;
> g_hash_table_insert(s->vtd_as_by_busptr, new_key, vtd_bus);
> }
> + return vtd_bus;
> +}
>
> +VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn)
> +{
> + VTDBus *vtd_bus;
> + VTDAddressSpace *vtd_dev_as;
> + char name[128];
> +
> + vtd_bus = vtd_find_add_bus(s, bus);
> vtd_dev_as = vtd_bus->dev_as[devfn];
>
> if (!vtd_dev_as) {
> @@ -3436,6 +3446,55 @@ VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn)
> return vtd_dev_as;
> }
>
> +static int vtd_dev_set_iommu_context(PCIBus *bus, void *opaque,
> + int devfn,
> + HostIOMMUContext *iommu_ctx)
> +{
> + IntelIOMMUState *s = opaque;
> + VTDBus *vtd_bus;
> + VTDHostIOMMUContext *vtd_dev_icx;
> +
> + assert(0 <= devfn && devfn < PCI_DEVFN_MAX);
> +
> + vtd_bus = vtd_find_add_bus(s, bus);
> +
> + vtd_iommu_lock(s);
> +
> + vtd_dev_icx = vtd_bus->dev_icx[devfn];
> +
> + assert(!vtd_dev_icx);
> +
> + vtd_bus->dev_icx[devfn] = vtd_dev_icx =
> + g_malloc0(sizeof(VTDHostIOMMUContext));
> + vtd_dev_icx->vtd_bus = vtd_bus;
> + vtd_dev_icx->devfn = (uint8_t)devfn;
> + vtd_dev_icx->iommu_state = s;
> + vtd_dev_icx->iommu_ctx = iommu_ctx;
> +
> + vtd_iommu_unlock(s);
> +
> + return 0;
> +}
> +
> +static void vtd_dev_unset_iommu_context(PCIBus *bus, void *opaque, int devfn)
> +{
> + IntelIOMMUState *s = opaque;
> + VTDBus *vtd_bus;
> + VTDHostIOMMUContext *vtd_dev_icx;
> +
> + assert(0 <= devfn && devfn < PCI_DEVFN_MAX);
> +
> + vtd_bus = vtd_find_add_bus(s, bus);
> +
> + vtd_iommu_lock(s);
> +
> + vtd_dev_icx = vtd_bus->dev_icx[devfn];
> + g_free(vtd_dev_icx);
> + vtd_bus->dev_icx[devfn] = NULL;
> +
> + vtd_iommu_unlock(s);
> +}
> +
> static uint64_t get_naturally_aligned_size(uint64_t start,
> uint64_t size, int gaw)
> {
> @@ -3731,6 +3790,8 @@ static AddressSpace *vtd_host_dma_iommu(PCIBus *bus, void *opaque, int devfn)
>
> static PCIIOMMUOps vtd_iommu_ops = {
> .get_address_space = vtd_host_dma_iommu,
> + .set_iommu_context = vtd_dev_set_iommu_context,
> + .unset_iommu_context = vtd_dev_unset_iommu_context,
> };
>
> static bool vtd_decide_config(IntelIOMMUState *s, Error **errp)
> diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
> index 3870052..b5fefb9 100644
> --- a/include/hw/i386/intel_iommu.h
> +++ b/include/hw/i386/intel_iommu.h
> @@ -64,6 +64,7 @@ typedef union VTD_IR_TableEntry VTD_IR_TableEntry;
> typedef union VTD_IR_MSIAddress VTD_IR_MSIAddress;
> typedef struct VTDPASIDDirEntry VTDPASIDDirEntry;
> typedef struct VTDPASIDEntry VTDPASIDEntry;
> +typedef struct VTDHostIOMMUContext VTDHostIOMMUContext;
>
> /* Context-Entry */
> struct VTDContextEntry {
> @@ -112,10 +113,20 @@ struct VTDAddressSpace {
> IOVATree *iova_tree; /* Traces mapped IOVA ranges */
> };
>
> +struct VTDHostIOMMUContext {
> + VTDBus *vtd_bus;
> + uint8_t devfn;
> + HostIOMMUContext *iommu_ctx;
I don't get why we don't have standard QOM inheritance instead of this
handle?
VTDHostContext parent_obj;
like IOMMUMemoryRegion <- MemoryRegion <- Object
> + IntelIOMMUState *iommu_state;
> +};
> +
> struct VTDBus {
> - PCIBus* bus; /* A reference to the bus to provide translation for */
> + /* A reference to the bus to provide translation for */
> + PCIBus *bus;
> /* A table of VTDAddressSpace objects indexed by devfn */
> - VTDAddressSpace *dev_as[];
> + VTDAddressSpace *dev_as[PCI_DEVFN_MAX];
> + /* A table of VTDHostIOMMUContext objects indexed by devfn */
> + VTDHostIOMMUContext *dev_icx[PCI_DEVFN_MAX];
At this point of the review, it is unclear to me why the context is
associated to a device. Up to now you have not explained it should. If
so why isn't it part of VTDAddressSpace?
Thanks
Eric
> };
>
> struct VTDIOTLBEntry {
> @@ -269,8 +280,10 @@ struct IntelIOMMUState {
> bool dma_drain; /* Whether DMA r/w draining enabled */
>
> /*
> - * Protects IOMMU states in general. Currently it protects the
> - * per-IOMMU IOTLB cache, and context entry cache in VTDAddressSpace.
> + * iommu_lock protects below:
> + * - per-IOMMU IOTLB caches
> + * - context entry cache in VTDAddressSpace
> + * - HostIOMMUContext pointer cached in vIOMMU
> */
> QemuMutex iommu_lock;
> };
>
Hi Eric,
> From: Auger Eric < eric.auger@redhat.com>
> Sent: Tuesday, March 31, 2020 4:24 AM
> To: Liu, Yi L <yi.l.liu@intel.com>; qemu-devel@nongnu.org;
> Subject: Re: [PATCH v2 07/22] intel_iommu: add set/unset_iommu_context callback
>
> Yi,
>
> On 3/30/20 6:24 AM, Liu Yi L wrote:
> > This patch adds set/unset_iommu_context() impelementation in Intel
> This patch implements the set/unset_iommu_context() ops for Intel vIOMMU.
> > vIOMMU. For Intel platform, pass-through modules (e.g. VFIO) could
> > set HostIOMMUContext to Intel vIOMMU emulator.
> >
> > Cc: Kevin Tian <kevin.tian@intel.com>
> > Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
> > Cc: Peter Xu <peterx@redhat.com>
> > Cc: Yi Sun <yi.y.sun@linux.intel.com>
> > Cc: Paolo Bonzini <pbonzini@redhat.com>
> > Cc: Richard Henderson <rth@twiddle.net>
> > Cc: Eduardo Habkost <ehabkost@redhat.com>
> > Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
> > ---
> > hw/i386/intel_iommu.c | 71
> ++++++++++++++++++++++++++++++++++++++++---
> > include/hw/i386/intel_iommu.h | 21 ++++++++++---
> > 2 files changed, 83 insertions(+), 9 deletions(-)
> >
> > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> > index 4b22910..fd349c6 100644
> > --- a/hw/i386/intel_iommu.c
> > +++ b/hw/i386/intel_iommu.c
> > @@ -3354,23 +3354,33 @@ static const MemoryRegionOps vtd_mem_ir_ops = {
> > },
> > };
> >
> > -VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn)
> > +/**
> > + * Fetch a VTDBus instance for given PCIBus. If no existing instance,
> > + * allocate one.
> > + */
> > +static VTDBus *vtd_find_add_bus(IntelIOMMUState *s, PCIBus *bus)
> > {
> > uintptr_t key = (uintptr_t)bus;
> > VTDBus *vtd_bus = g_hash_table_lookup(s->vtd_as_by_busptr, &key);
> > - VTDAddressSpace *vtd_dev_as;
> > - char name[128];
> >
> > if (!vtd_bus) {
> > uintptr_t *new_key = g_malloc(sizeof(*new_key));
> > *new_key = (uintptr_t)bus;
> > /* No corresponding free() */
> > - vtd_bus = g_malloc0(sizeof(VTDBus) + sizeof(VTDAddressSpace *) * \
> > - PCI_DEVFN_MAX);
> > + vtd_bus = g_malloc0(sizeof(VTDBus));
> > vtd_bus->bus = bus;
> > g_hash_table_insert(s->vtd_as_by_busptr, new_key, vtd_bus);
> > }
> > + return vtd_bus;
> > +}
> >
> > +VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn)
> > +{
> > + VTDBus *vtd_bus;
> > + VTDAddressSpace *vtd_dev_as;
> > + char name[128];
> > +
> > + vtd_bus = vtd_find_add_bus(s, bus);
> > vtd_dev_as = vtd_bus->dev_as[devfn];
> >
> > if (!vtd_dev_as) {
> > @@ -3436,6 +3446,55 @@ VTDAddressSpace
> *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn)
> > return vtd_dev_as;
> > }
> >
> > +static int vtd_dev_set_iommu_context(PCIBus *bus, void *opaque,
> > + int devfn,
> > + HostIOMMUContext *iommu_ctx)
> > +{
> > + IntelIOMMUState *s = opaque;
> > + VTDBus *vtd_bus;
> > + VTDHostIOMMUContext *vtd_dev_icx;
> > +
> > + assert(0 <= devfn && devfn < PCI_DEVFN_MAX);
> > +
> > + vtd_bus = vtd_find_add_bus(s, bus);
> > +
> > + vtd_iommu_lock(s);
> > +
> > + vtd_dev_icx = vtd_bus->dev_icx[devfn];
> > +
> > + assert(!vtd_dev_icx);
> > +
> > + vtd_bus->dev_icx[devfn] = vtd_dev_icx =
> > + g_malloc0(sizeof(VTDHostIOMMUContext));
> > + vtd_dev_icx->vtd_bus = vtd_bus;
> > + vtd_dev_icx->devfn = (uint8_t)devfn;
> > + vtd_dev_icx->iommu_state = s;
> > + vtd_dev_icx->iommu_ctx = iommu_ctx;
> > +
> > + vtd_iommu_unlock(s);
> > +
> > + return 0;
> > +}
> > +
> > +static void vtd_dev_unset_iommu_context(PCIBus *bus, void *opaque, int devfn)
> > +{
> > + IntelIOMMUState *s = opaque;
> > + VTDBus *vtd_bus;
> > + VTDHostIOMMUContext *vtd_dev_icx;
> > +
> > + assert(0 <= devfn && devfn < PCI_DEVFN_MAX);
> > +
> > + vtd_bus = vtd_find_add_bus(s, bus);
> > +
> > + vtd_iommu_lock(s);
> > +
> > + vtd_dev_icx = vtd_bus->dev_icx[devfn];
> > + g_free(vtd_dev_icx);
> > + vtd_bus->dev_icx[devfn] = NULL;
> > +
> > + vtd_iommu_unlock(s);
> > +}
> > +
> > static uint64_t get_naturally_aligned_size(uint64_t start,
> > uint64_t size, int gaw)
> > {
> > @@ -3731,6 +3790,8 @@ static AddressSpace *vtd_host_dma_iommu(PCIBus
> *bus, void *opaque, int devfn)
> >
> > static PCIIOMMUOps vtd_iommu_ops = {
> > .get_address_space = vtd_host_dma_iommu,
> > + .set_iommu_context = vtd_dev_set_iommu_context,
> > + .unset_iommu_context = vtd_dev_unset_iommu_context,
> > };
> >
> > static bool vtd_decide_config(IntelIOMMUState *s, Error **errp)
> > diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
> > index 3870052..b5fefb9 100644
> > --- a/include/hw/i386/intel_iommu.h
> > +++ b/include/hw/i386/intel_iommu.h
> > @@ -64,6 +64,7 @@ typedef union VTD_IR_TableEntry VTD_IR_TableEntry;
> > typedef union VTD_IR_MSIAddress VTD_IR_MSIAddress;
> > typedef struct VTDPASIDDirEntry VTDPASIDDirEntry;
> > typedef struct VTDPASIDEntry VTDPASIDEntry;
> > +typedef struct VTDHostIOMMUContext VTDHostIOMMUContext;
> >
> > /* Context-Entry */
> > struct VTDContextEntry {
> > @@ -112,10 +113,20 @@ struct VTDAddressSpace {
> > IOVATree *iova_tree; /* Traces mapped IOVA ranges */
> > };
> >
> > +struct VTDHostIOMMUContext {
>
>
> > + VTDBus *vtd_bus;
> > + uint8_t devfn;
> > + HostIOMMUContext *iommu_ctx;
> I don't get why we don't have standard QOM inheritance instead of this
> handle?
> VTDHostContext parent_obj;
>
> like IOMMUMemoryRegion <- MemoryRegion <- Object
Here it is not inherit the object. It's just cache the HostIOMMUContext
pointer in vIOMMU. Just like AddressSpace, it has a MemoryRegion pointer.
Here is the same, VTDHostIOMMUContext is just a wrapper to better manage
it in vVT-d. It's not inheriting.
> > + IntelIOMMUState *iommu_state;
> > +};
> > +
> > struct VTDBus {
> > - PCIBus* bus; /* A reference to the bus to provide translation for
> */
> > + /* A reference to the bus to provide translation for */
> > + PCIBus *bus;
> > /* A table of VTDAddressSpace objects indexed by devfn */
> > - VTDAddressSpace *dev_as[];
> > + VTDAddressSpace *dev_as[PCI_DEVFN_MAX];
> > + /* A table of VTDHostIOMMUContext objects indexed by devfn */
> > + VTDHostIOMMUContext *dev_icx[PCI_DEVFN_MAX];
> At this point of the review, it is unclear to me why the context is
> associated to a device.
HostIOMMUContext can be per-device or not. It depends on how vIOMMU
manage it. For vVT-d, it's per device as the container is per-device.
> Up to now you have not explained it should. If
> so why isn't it part of VTDAddressSpace?
Ah, I did have considered it. But I chose to use a separate one as
context is not really tied with an addresspace. It's better to mange
it with a separate structure.
Regards,
Yi Liu
Hi Yi,
On 3/31/20 2:25 PM, Liu, Yi L wrote:
> Hi Eric,
>
>> From: Auger Eric < eric.auger@redhat.com>
>> Sent: Tuesday, March 31, 2020 4:24 AM
>> To: Liu, Yi L <yi.l.liu@intel.com>; qemu-devel@nongnu.org;
>> Subject: Re: [PATCH v2 07/22] intel_iommu: add set/unset_iommu_context callback
>>
>> Yi,
>>
>> On 3/30/20 6:24 AM, Liu Yi L wrote:
>>> This patch adds set/unset_iommu_context() impelementation in Intel
>> This patch implements the set/unset_iommu_context() ops for Intel vIOMMU.
>>> vIOMMU. For Intel platform, pass-through modules (e.g. VFIO) could
>>> set HostIOMMUContext to Intel vIOMMU emulator.
>>>
>>> Cc: Kevin Tian <kevin.tian@intel.com>
>>> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com>
>>> Cc: Peter Xu <peterx@redhat.com>
>>> Cc: Yi Sun <yi.y.sun@linux.intel.com>
>>> Cc: Paolo Bonzini <pbonzini@redhat.com>
>>> Cc: Richard Henderson <rth@twiddle.net>
>>> Cc: Eduardo Habkost <ehabkost@redhat.com>
>>> Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
>>> ---
>>> hw/i386/intel_iommu.c | 71
>> ++++++++++++++++++++++++++++++++++++++++---
>>> include/hw/i386/intel_iommu.h | 21 ++++++++++---
>>> 2 files changed, 83 insertions(+), 9 deletions(-)
>>>
>>> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
>>> index 4b22910..fd349c6 100644
>>> --- a/hw/i386/intel_iommu.c
>>> +++ b/hw/i386/intel_iommu.c
>>> @@ -3354,23 +3354,33 @@ static const MemoryRegionOps vtd_mem_ir_ops = {
>>> },
>>> };
>>>
>>> -VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn)
>>> +/**
>>> + * Fetch a VTDBus instance for given PCIBus. If no existing instance,
>>> + * allocate one.
>>> + */
>>> +static VTDBus *vtd_find_add_bus(IntelIOMMUState *s, PCIBus *bus)
>>> {
>>> uintptr_t key = (uintptr_t)bus;
>>> VTDBus *vtd_bus = g_hash_table_lookup(s->vtd_as_by_busptr, &key);
>>> - VTDAddressSpace *vtd_dev_as;
>>> - char name[128];
>>>
>>> if (!vtd_bus) {
>>> uintptr_t *new_key = g_malloc(sizeof(*new_key));
>>> *new_key = (uintptr_t)bus;
>>> /* No corresponding free() */
>>> - vtd_bus = g_malloc0(sizeof(VTDBus) + sizeof(VTDAddressSpace *) * \
>>> - PCI_DEVFN_MAX);
>>> + vtd_bus = g_malloc0(sizeof(VTDBus));
>>> vtd_bus->bus = bus;
>>> g_hash_table_insert(s->vtd_as_by_busptr, new_key, vtd_bus);
>>> }
>>> + return vtd_bus;
>>> +}
>>>
>>> +VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn)
>>> +{
>>> + VTDBus *vtd_bus;
>>> + VTDAddressSpace *vtd_dev_as;
>>> + char name[128];
>>> +
>>> + vtd_bus = vtd_find_add_bus(s, bus);
>>> vtd_dev_as = vtd_bus->dev_as[devfn];
>>>
>>> if (!vtd_dev_as) {
>>> @@ -3436,6 +3446,55 @@ VTDAddressSpace
>> *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn)
>>> return vtd_dev_as;
>>> }
>>>
>>> +static int vtd_dev_set_iommu_context(PCIBus *bus, void *opaque,
>>> + int devfn,
>>> + HostIOMMUContext *iommu_ctx)
>>> +{
>>> + IntelIOMMUState *s = opaque;
>>> + VTDBus *vtd_bus;
>>> + VTDHostIOMMUContext *vtd_dev_icx;
>>> +
>>> + assert(0 <= devfn && devfn < PCI_DEVFN_MAX);
>>> +
>>> + vtd_bus = vtd_find_add_bus(s, bus);
>>> +
>>> + vtd_iommu_lock(s);
>>> +
>>> + vtd_dev_icx = vtd_bus->dev_icx[devfn];
>>> +
>>> + assert(!vtd_dev_icx);
>>> +
>>> + vtd_bus->dev_icx[devfn] = vtd_dev_icx =
>>> + g_malloc0(sizeof(VTDHostIOMMUContext));
>>> + vtd_dev_icx->vtd_bus = vtd_bus;
>>> + vtd_dev_icx->devfn = (uint8_t)devfn;
>>> + vtd_dev_icx->iommu_state = s;
>>> + vtd_dev_icx->iommu_ctx = iommu_ctx;
>>> +
>>> + vtd_iommu_unlock(s);
>>> +
>>> + return 0;
>>> +}
>>> +
>>> +static void vtd_dev_unset_iommu_context(PCIBus *bus, void *opaque, int devfn)
>>> +{
>>> + IntelIOMMUState *s = opaque;
>>> + VTDBus *vtd_bus;
>>> + VTDHostIOMMUContext *vtd_dev_icx;
>>> +
>>> + assert(0 <= devfn && devfn < PCI_DEVFN_MAX);
>>> +
>>> + vtd_bus = vtd_find_add_bus(s, bus);
>>> +
>>> + vtd_iommu_lock(s);
>>> +
>>> + vtd_dev_icx = vtd_bus->dev_icx[devfn];
>>> + g_free(vtd_dev_icx);
>>> + vtd_bus->dev_icx[devfn] = NULL;
>>> +
>>> + vtd_iommu_unlock(s);
>>> +}
>>> +
>>> static uint64_t get_naturally_aligned_size(uint64_t start,
>>> uint64_t size, int gaw)
>>> {
>>> @@ -3731,6 +3790,8 @@ static AddressSpace *vtd_host_dma_iommu(PCIBus
>> *bus, void *opaque, int devfn)
>>>
>>> static PCIIOMMUOps vtd_iommu_ops = {
>>> .get_address_space = vtd_host_dma_iommu,
>>> + .set_iommu_context = vtd_dev_set_iommu_context,
>>> + .unset_iommu_context = vtd_dev_unset_iommu_context,
>>> };
>>>
>>> static bool vtd_decide_config(IntelIOMMUState *s, Error **errp)
>>> diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
>>> index 3870052..b5fefb9 100644
>>> --- a/include/hw/i386/intel_iommu.h
>>> +++ b/include/hw/i386/intel_iommu.h
>>> @@ -64,6 +64,7 @@ typedef union VTD_IR_TableEntry VTD_IR_TableEntry;
>>> typedef union VTD_IR_MSIAddress VTD_IR_MSIAddress;
>>> typedef struct VTDPASIDDirEntry VTDPASIDDirEntry;
>>> typedef struct VTDPASIDEntry VTDPASIDEntry;
>>> +typedef struct VTDHostIOMMUContext VTDHostIOMMUContext;
>>>
>>> /* Context-Entry */
>>> struct VTDContextEntry {
>>> @@ -112,10 +113,20 @@ struct VTDAddressSpace {
>>> IOVATree *iova_tree; /* Traces mapped IOVA ranges */
>>> };
>>>
>>> +struct VTDHostIOMMUContext {
>>
>>
>>> + VTDBus *vtd_bus;
>>> + uint8_t devfn;
>>> + HostIOMMUContext *iommu_ctx;
>> I don't get why we don't have standard QOM inheritance instead of this
>> handle?
>> VTDHostContext parent_obj;
>>
>> like IOMMUMemoryRegion <- MemoryRegion <- Object
>
> Here it is not inherit the object. It's just cache the HostIOMMUContext
> pointer in vIOMMU. Just like AddressSpace, it has a MemoryRegion pointer.
> Here is the same, VTDHostIOMMUContext is just a wrapper to better manage
> it in vVT-d. It's not inheriting.
Yep I've got it now ;-)
>
>>> + IntelIOMMUState *iommu_state;
>>> +};
>>> +
>>> struct VTDBus {
>>> - PCIBus* bus; /* A reference to the bus to provide translation for
>> */
>>> + /* A reference to the bus to provide translation for */
>>> + PCIBus *bus;
>>> /* A table of VTDAddressSpace objects indexed by devfn */
>>> - VTDAddressSpace *dev_as[];
>>> + VTDAddressSpace *dev_as[PCI_DEVFN_MAX];
>>> + /* A table of VTDHostIOMMUContext objects indexed by devfn */
>>> + VTDHostIOMMUContext *dev_icx[PCI_DEVFN_MAX];
>> At this point of the review, it is unclear to me why the context is
>> associated to a device.
>
> HostIOMMUContext can be per-device or not. It depends on how vIOMMU
> manage it. For vVT-d, it's per device as the container is per-device.
>
>> Up to now you have not explained it should. If
>> so why isn't it part of VTDAddressSpace?
>
> Ah, I did have considered it. But I chose to use a separate one as
> context is not really tied with an addresspace. It's better to mange
> it with a separate structure.
OK
Thanks
Eric
>
> Regards,
> Yi Liu
>
© 2016 - 2026 Red Hat, Inc.