Message ID | 1499847223-8078-3-git-send-email-peterx@redhat.com |
---|---|
State | New |
Headers | show |
On Wed, Jul 12, 2017 at 04:13:41PM +0800, Peter Xu wrote: > We were having static IOTLB size as 1024. Let it be a tunable. We can > also turns IOTLB off if we want, by specify the size as zero. > > The tunable is named as "x-iotlb-size" since that should not really be > something used by user yet, but mostly for debugging purpose now. > > Signed-off-by: Peter Xu <peterx@redhat.com> I'm somewhat vary of adding tunables just for developers to play with. People will find and abuse them :) > --- > hw/i386/intel_iommu.c | 11 ++++++++++- > hw/i386/intel_iommu_internal.h | 1 - > include/hw/i386/intel_iommu.h | 1 + > 3 files changed, 11 insertions(+), 2 deletions(-) > > diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c > index 392da45..9c36866 100644 > --- a/hw/i386/intel_iommu.c > +++ b/hw/i386/intel_iommu.c > @@ -222,6 +222,10 @@ static VTDIOTLBEntry *vtd_lookup_iotlb(IntelIOMMUState *s, uint16_t source_id, > uint64_t key; > int level; > > + if (s->iotlb_size == 0) { > + return NULL; > + } > + > for (level = VTD_SL_PT_LEVEL; level < VTD_SL_PML4_LEVEL; level++) { > key = vtd_get_iotlb_key(vtd_get_iotlb_gfn(addr, level), > source_id, level); > @@ -244,8 +248,12 @@ static void vtd_update_iotlb(IntelIOMMUState *s, uint16_t source_id, > uint64_t *key = g_malloc(sizeof(*key)); > uint64_t gfn = vtd_get_iotlb_gfn(addr, level); > > + if (s->iotlb_size == 0) { > + return; > + } > + > trace_vtd_iotlb_page_update(source_id, addr, slpte, domain_id); > - if (g_hash_table_size(s->iotlb) >= VTD_IOTLB_MAX_SIZE) { > + if (g_hash_table_size(s->iotlb) >= s->iotlb_size) { > trace_vtd_iotlb_reset("iotlb exceeds size limit"); > vtd_reset_iotlb(s); > } > @@ -2397,6 +2405,7 @@ static Property vtd_properties[] = { > ON_OFF_AUTO_AUTO), > DEFINE_PROP_BOOL("x-buggy-eim", IntelIOMMUState, buggy_eim, false), > DEFINE_PROP_BOOL("caching-mode", IntelIOMMUState, caching_mode, FALSE), > + DEFINE_PROP_UINT16("x-iotlb-size", IntelIOMMUState, iotlb_size, 1024), > DEFINE_PROP_END_OF_LIST(), > }; > > diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h > index 754cf8a..2d77249 100644 > --- a/hw/i386/intel_iommu_internal.h > +++ b/hw/i386/intel_iommu_internal.h > @@ -116,7 +116,6 @@ > /* The shift of source_id in the key of IOTLB hash table */ > #define VTD_IOTLB_SID_SHIFT 36 > #define VTD_IOTLB_LVL_SHIFT 52 > -#define VTD_IOTLB_MAX_SIZE 1024 /* Max size of the hash table */ > > /* IOTLB_REG */ > #define VTD_TLB_GLOBAL_FLUSH (1ULL << 60) /* Global invalidation */ > diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h > index 3e51876..a57f419 100644 > --- a/include/hw/i386/intel_iommu.h > +++ b/include/hw/i386/intel_iommu.h > @@ -288,6 +288,7 @@ struct IntelIOMMUState { > > uint32_t context_cache_gen; /* Should be in [1,MAX] */ > GHashTable *iotlb; /* IOTLB */ > + uint16_t iotlb_size; /* IOTLB max cache entries */ > > MemoryRegionIOMMUOps iommu_ops; > GHashTable *vtd_as_by_busptr; /* VTDBus objects indexed by PCIBus* reference */ > -- > 2.7.4
On Thu, Jul 13, 2017 at 08:47:00PM +0300, Michael S. Tsirkin wrote: > On Wed, Jul 12, 2017 at 04:13:41PM +0800, Peter Xu wrote: > > We were having static IOTLB size as 1024. Let it be a tunable. We can > > also turns IOTLB off if we want, by specify the size as zero. > > > > The tunable is named as "x-iotlb-size" since that should not really be > > something used by user yet, but mostly for debugging purpose now. > > > > Signed-off-by: Peter Xu <peterx@redhat.com> > > I'm somewhat vary of adding tunables just for developers to play with. > People will find and abuse them :) I would think it convenient (especially with "x-") and I would never worry about people using it (I really see nothing dangerous...). But if you don't like it, I can drop it in next version for sure. Thanks,
diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c index 392da45..9c36866 100644 --- a/hw/i386/intel_iommu.c +++ b/hw/i386/intel_iommu.c @@ -222,6 +222,10 @@ static VTDIOTLBEntry *vtd_lookup_iotlb(IntelIOMMUState *s, uint16_t source_id, uint64_t key; int level; + if (s->iotlb_size == 0) { + return NULL; + } + for (level = VTD_SL_PT_LEVEL; level < VTD_SL_PML4_LEVEL; level++) { key = vtd_get_iotlb_key(vtd_get_iotlb_gfn(addr, level), source_id, level); @@ -244,8 +248,12 @@ static void vtd_update_iotlb(IntelIOMMUState *s, uint16_t source_id, uint64_t *key = g_malloc(sizeof(*key)); uint64_t gfn = vtd_get_iotlb_gfn(addr, level); + if (s->iotlb_size == 0) { + return; + } + trace_vtd_iotlb_page_update(source_id, addr, slpte, domain_id); - if (g_hash_table_size(s->iotlb) >= VTD_IOTLB_MAX_SIZE) { + if (g_hash_table_size(s->iotlb) >= s->iotlb_size) { trace_vtd_iotlb_reset("iotlb exceeds size limit"); vtd_reset_iotlb(s); } @@ -2397,6 +2405,7 @@ static Property vtd_properties[] = { ON_OFF_AUTO_AUTO), DEFINE_PROP_BOOL("x-buggy-eim", IntelIOMMUState, buggy_eim, false), DEFINE_PROP_BOOL("caching-mode", IntelIOMMUState, caching_mode, FALSE), + DEFINE_PROP_UINT16("x-iotlb-size", IntelIOMMUState, iotlb_size, 1024), DEFINE_PROP_END_OF_LIST(), }; diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h index 754cf8a..2d77249 100644 --- a/hw/i386/intel_iommu_internal.h +++ b/hw/i386/intel_iommu_internal.h @@ -116,7 +116,6 @@ /* The shift of source_id in the key of IOTLB hash table */ #define VTD_IOTLB_SID_SHIFT 36 #define VTD_IOTLB_LVL_SHIFT 52 -#define VTD_IOTLB_MAX_SIZE 1024 /* Max size of the hash table */ /* IOTLB_REG */ #define VTD_TLB_GLOBAL_FLUSH (1ULL << 60) /* Global invalidation */ diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h index 3e51876..a57f419 100644 --- a/include/hw/i386/intel_iommu.h +++ b/include/hw/i386/intel_iommu.h @@ -288,6 +288,7 @@ struct IntelIOMMUState { uint32_t context_cache_gen; /* Should be in [1,MAX] */ GHashTable *iotlb; /* IOTLB */ + uint16_t iotlb_size; /* IOTLB max cache entries */ MemoryRegionIOMMUOps iommu_ops; GHashTable *vtd_as_by_busptr; /* VTDBus objects indexed by PCIBus* reference */
We were having static IOTLB size as 1024. Let it be a tunable. We can also turns IOTLB off if we want, by specify the size as zero. The tunable is named as "x-iotlb-size" since that should not really be something used by user yet, but mostly for debugging purpose now. Signed-off-by: Peter Xu <peterx@redhat.com> --- hw/i386/intel_iommu.c | 11 ++++++++++- hw/i386/intel_iommu_internal.h | 1 - include/hw/i386/intel_iommu.h | 1 + 3 files changed, 11 insertions(+), 2 deletions(-)