Re: [Qemu-devel] [PATCH v2 2/2] intel_iommu: Drop extended root field

[Dr. David Alan Gilbert]

* Peter Xu (address@hidden) wrote:
> VTD_RTADDR_RTT is dropped even by the VT-d spec, so QEMU should
> probably do the same thing (after all we never really implemented it).
> Since we've had a field for that in the migration stream, to keep
> compatibility we need to fill the hole up.
> 
> Please refer to VT-d spec 10.4.6.
> 
> Signed-off-by: Peter Xu <address@hidden>
> ---
>  hw/i386/intel_iommu.c          | 6 ++----
>  hw/i386/intel_iommu_internal.h | 1 -
>  hw/i386/trace-events           | 2 +-
>  include/hw/i386/intel_iommu.h  | 1 -
>  4 files changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
> index 21c6176b4a..1e452e5861 100644
> --- a/hw/i386/intel_iommu.c
> +++ b/hw/i386/intel_iommu.c
> @@ -1718,12 +1718,11 @@ error:
>  static void vtd_root_table_setup(IntelIOMMUState *s)
>  {
>      s->root = vtd_get_quad_raw(s, DMAR_RTADDR_REG);
> -    s->root_extended = s->root & VTD_RTADDR_RTT;
>      s->root &= VTD_RTADDR_ADDR_MASK(s->aw_bits);
>  
>      vtd_update_scalable_state(s);
>  
> -    trace_vtd_reg_dmar_root(s->root, s->root_extended);
> +    trace_vtd_reg_dmar_root(s->root, s->root_scalable);
>  }
>  
>  static void vtd_iec_notify_all(IntelIOMMUState *s, bool global,
> @@ -2982,7 +2981,7 @@ static const VMStateDescription vtd_vmstate = {
>          VMSTATE_UINT16(next_frcd_reg, IntelIOMMUState),
>          VMSTATE_UINT8_ARRAY(csr, IntelIOMMUState, DMAR_REG_SIZE),
>          VMSTATE_UINT8(iq_last_desc_type, IntelIOMMUState),
> -        VMSTATE_BOOL(root_extended, IntelIOMMUState),
> +        VMSTATE_UNUSED(1),      /* bool root_extended is obsolete by VT-d */

Yep, better.


Acked-by: Dr. David Alan Gilbert <address@hidden>

>          VMSTATE_BOOL(dmar_enabled, IntelIOMMUState),
>          VMSTATE_BOOL(qi_enabled, IntelIOMMUState),
>          VMSTATE_BOOL(intr_enabled, IntelIOMMUState),
> @@ -3493,7 +3492,6 @@ static void vtd_init(IntelIOMMUState *s)
>      memset(s->womask, 0, DMAR_REG_SIZE);
>  
>      s->root = 0;
> -    s->root_extended = false;
>      s->root_scalable = false;
>      s->dmar_enabled = false;
>      s->intr_enabled = false;
> diff --git a/hw/i386/intel_iommu_internal.h b/hw/i386/intel_iommu_internal.h
> index 1160618177..c1235a7063 100644
> --- a/hw/i386/intel_iommu_internal.h
> +++ b/hw/i386/intel_iommu_internal.h
> @@ -171,7 +171,6 @@
>  #define VTD_CCMD_FM(val)            (((val) >> 32) & 3ULL)
>  
>  /* RTADDR_REG */
> -#define VTD_RTADDR_RTT              (1ULL << 11)
>  #define VTD_RTADDR_SMT              (1ULL << 10)
>  #define VTD_RTADDR_ADDR_MASK(aw)    (VTD_HAW_MASK(aw) ^ 0xfffULL)
>  
> diff --git a/hw/i386/trace-events b/hw/i386/trace-events
> index 83f8369778..c8bc464bc5 100644
> --- a/hw/i386/trace-events
> +++ b/hw/i386/trace-events
> @@ -45,7 +45,7 @@ vtd_pt_enable_fast_path(uint16_t sid, bool success) "sid 
> 0x%"PRIu16" %d"
>  vtd_irq_generate(uint64_t addr, uint64_t data) "addr 0x%"PRIx64" data 
> 0x%"PRIx64
>  vtd_reg_read(uint64_t addr, uint64_t size) "addr 0x%"PRIx64" size 0x%"PRIx64
>  vtd_reg_write(uint64_t addr, uint64_t size, uint64_t val) "addr 0x%"PRIx64" 
> size 0x%"PRIx64" value 0x%"PRIx64
> -vtd_reg_dmar_root(uint64_t addr, bool extended) "addr 0x%"PRIx64" extended 
> %d"
> +vtd_reg_dmar_root(uint64_t addr, bool scalable) "addr 0x%"PRIx64" scalable 
> %d"
>  vtd_reg_ir_root(uint64_t addr, uint32_t size) "addr 0x%"PRIx64" size 
> 0x%"PRIx32
>  vtd_reg_write_gcmd(uint32_t status, uint32_t val) "status 0x%"PRIx32" value 
> 0x%"PRIx32
>  vtd_reg_write_fectl(uint32_t value) "value 0x%"PRIx32
> diff --git a/include/hw/i386/intel_iommu.h b/include/hw/i386/intel_iommu.h
> index c11e3d5b34..199a813eee 100644
> --- a/include/hw/i386/intel_iommu.h
> +++ b/include/hw/i386/intel_iommu.h
> @@ -231,7 +231,6 @@ struct IntelIOMMUState {
>      bool scalable_mode;             /* RO - is Scalable Mode supported? */
>  
>      dma_addr_t root;                /* Current root table pointer */
> -    bool root_extended;             /* Type of root table (extended or not) 
> */
>      bool root_scalable;             /* Type of root table (scalable or not) 
> */
>      bool dmar_enabled;              /* Set if DMA remapping is enabled */
>  
> -- 
> 2.17.1
> 
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK