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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen staging] AMD/IOMMU: Treat guest head/tail pointers as byte offsets
commit 40bc1b0c1995cfac0d0da7b9069e944392dafc14
Author: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Mon Feb 3 13:50:34 2020 +0000
Commit: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Mon Feb 10 16:14:17 2020 +0000
AMD/IOMMU: Treat guest head/tail pointers as byte offsets
The MMIO registers as already formatted as byte offsets. Start by masking
out
reserved bits, which fixes an implementation bug (reserved bits should be
read-only zero, rather than preserving their previously-written value). As
a
consequence, we can use the values directly, instead of masking/shifting on
every use.
Store the buffer size, rather than the number of entries, to keep the same
units for comparison purposes.
This simplifies guest_iommu_get_table_mfn() by dropping the entry_size
parameter, and simplifies the map_domain_page() handling by being able to
drop
the log_base variables.
Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
---
xen/drivers/passthrough/amd/iommu.h | 2 +-
xen/drivers/passthrough/amd/iommu_guest.c | 85 +++++++++++++++----------------
2 files changed, 42 insertions(+), 45 deletions(-)
diff --git a/xen/drivers/passthrough/amd/iommu.h
b/xen/drivers/passthrough/amd/iommu.h
index 81b6812d3a..0b598d06f8 100644
--- a/xen/drivers/passthrough/amd/iommu.h
+++ b/xen/drivers/passthrough/amd/iommu.h
@@ -152,7 +152,7 @@ struct guest_buffer {
struct mmio_reg reg_base;
struct mmio_reg reg_tail;
struct mmio_reg reg_head;
- uint32_t entries;
+ uint32_t size;
};
struct guest_iommu_msi {
diff --git a/xen/drivers/passthrough/amd/iommu_guest.c
b/xen/drivers/passthrough/amd/iommu_guest.c
index d05901d348..014a72a54b 100644
--- a/xen/drivers/passthrough/amd/iommu_guest.c
+++ b/xen/drivers/passthrough/amd/iommu_guest.c
@@ -103,14 +103,13 @@ static void guest_iommu_deliver_msi(struct domain *d)
static unsigned long guest_iommu_get_table_mfn(struct domain *d,
uint64_t base_raw,
- unsigned int entry_size,
unsigned int pos)
{
unsigned long idx, gfn, mfn;
p2m_type_t p2mt;
gfn = get_gfn_from_base_reg(base_raw);
- idx = (pos * entry_size) >> PAGE_SHIFT;
+ idx = pos >> PAGE_SHIFT;
mfn = mfn_x(get_gfn(d, gfn + idx, &p2mt));
put_gfn(d, gfn);
@@ -133,14 +132,14 @@ static void guest_iommu_enable_ring_buffer(struct
guest_iommu *iommu,
uint32_t length_raw = get_field_from_reg_u32(buffer->reg_base.hi,
RING_BF_LENGTH_MASK,
RING_BF_LENGTH_SHIFT);
- buffer->entries = 1 << length_raw;
+ buffer->size = entry_size << length_raw;
}
void guest_iommu_add_ppr_log(struct domain *d, u32 entry[])
{
uint16_t gdev_id;
unsigned long mfn, tail, head;
- ppr_entry_t *log, *log_base;
+ ppr_entry_t *log;
struct guest_iommu *iommu;
if ( !is_hvm_domain(d) )
@@ -150,10 +149,10 @@ void guest_iommu_add_ppr_log(struct domain *d, u32
entry[])
if ( !iommu )
return;
- tail = iommu_get_rb_pointer(iommu->ppr_log.reg_tail.lo);
- head = iommu_get_rb_pointer(iommu->ppr_log.reg_head.lo);
+ tail = iommu->ppr_log.reg_tail.lo;
+ head = iommu->ppr_log.reg_head.lo;
- if ( tail >= iommu->ppr_log.entries || head >= iommu->ppr_log.entries )
+ if ( tail >= iommu->ppr_log.size || head >= iommu->ppr_log.size )
{
AMD_IOMMU_DEBUG("Error: guest iommu ppr log overflows\n");
guest_iommu_disable(iommu);
@@ -161,11 +160,10 @@ void guest_iommu_add_ppr_log(struct domain *d, u32
entry[])
}
mfn = guest_iommu_get_table_mfn(d, reg_to_u64(iommu->ppr_log.reg_base),
- sizeof(ppr_entry_t), tail);
+ tail);
ASSERT(mfn_valid(_mfn(mfn)));
- log_base = map_domain_page(_mfn(mfn));
- log = log_base + tail % (PAGE_SIZE / sizeof(ppr_entry_t));
+ log = map_domain_page(_mfn(mfn)) + (tail & ~PAGE_MASK);
/* Convert physical device id back into virtual device id */
gdev_id = guest_bdf(d, iommu_get_devid_from_cmd(entry[0]));
@@ -174,13 +172,15 @@ void guest_iommu_add_ppr_log(struct domain *d, u32
entry[])
memcpy(log, entry, sizeof(ppr_entry_t));
/* Now shift ppr log tail pointer */
- if ( ++tail >= iommu->ppr_log.entries )
+ tail += sizeof(ppr_entry_t);
+ if ( tail >= iommu->ppr_log.size )
{
tail = 0;
iommu->reg_status.lo |= IOMMU_STATUS_PPR_LOG_OVERFLOW;
}
- iommu_set_rb_pointer(&iommu->ppr_log.reg_tail.lo, tail);
- unmap_domain_page(log_base);
+
+ iommu->ppr_log.reg_tail.lo = tail;
+ unmap_domain_page(log);
guest_iommu_deliver_msi(d);
}
@@ -189,7 +189,7 @@ void guest_iommu_add_event_log(struct domain *d, u32
entry[])
{
uint16_t dev_id;
unsigned long mfn, tail, head;
- event_entry_t *log, *log_base;
+ event_entry_t *log;
struct guest_iommu *iommu;
if ( !is_hvm_domain(d) )
@@ -199,10 +199,10 @@ void guest_iommu_add_event_log(struct domain *d, u32
entry[])
if ( !iommu )
return;
- tail = iommu_get_rb_pointer(iommu->event_log.reg_tail.lo);
- head = iommu_get_rb_pointer(iommu->event_log.reg_head.lo);
+ tail = iommu->event_log.reg_tail.lo;
+ head = iommu->event_log.reg_head.lo;
- if ( tail >= iommu->event_log.entries || head >= iommu->event_log.entries )
+ if ( tail >= iommu->event_log.size || head >= iommu->event_log.size )
{
AMD_IOMMU_DEBUG("Error: guest iommu event overflows\n");
guest_iommu_disable(iommu);
@@ -210,11 +210,10 @@ void guest_iommu_add_event_log(struct domain *d, u32
entry[])
}
mfn = guest_iommu_get_table_mfn(d, reg_to_u64(iommu->event_log.reg_base),
- sizeof(event_entry_t), tail);
+ tail);
ASSERT(mfn_valid(_mfn(mfn)));
- log_base = map_domain_page(_mfn(mfn));
- log = log_base + tail % (PAGE_SIZE / sizeof(event_entry_t));
+ log = map_domain_page(_mfn(mfn)) + (tail & ~PAGE_MASK);
/* re-write physical device id into virtual device id */
dev_id = guest_bdf(d, iommu_get_devid_from_cmd(entry[0]));
@@ -222,14 +221,15 @@ void guest_iommu_add_event_log(struct domain *d, u32
entry[])
memcpy(log, entry, sizeof(event_entry_t));
/* Now shift event log tail pointer */
- if ( ++tail >= iommu->event_log.entries )
+ tail += sizeof(event_entry_t);
+ if ( tail >= iommu->event_log.size )
{
tail = 0;
iommu->reg_status.lo |= IOMMU_STATUS_EVENT_LOG_OVERFLOW;
}
- iommu_set_rb_pointer(&iommu->event_log.reg_tail.lo, tail);
- unmap_domain_page(log_base);
+ iommu->event_log.reg_tail.lo = tail;
+ unmap_domain_page(log);
guest_iommu_deliver_msi(d);
}
@@ -379,7 +379,7 @@ static int do_invalidate_dte(struct domain *d, cmd_entry_t
*cmd)
dte_mfn = guest_iommu_get_table_mfn(d,
reg_to_u64(g_iommu->dev_table.reg_base),
- sizeof(struct amd_iommu_dte), gbdf);
+ sizeof(struct amd_iommu_dte) * gbdf);
ASSERT(mfn_valid(_mfn(dte_mfn)));
/* Read guest dte information */
@@ -428,8 +428,8 @@ static int do_invalidate_dte(struct domain *d, cmd_entry_t
*cmd)
static void guest_iommu_process_command(void *data)
{
- unsigned long opcode, tail, head, entries_per_page, cmd_mfn;
- cmd_entry_t *cmd, *cmd_base;
+ unsigned long opcode, tail, head, cmd_mfn;
+ cmd_entry_t *cmd;
struct domain *d = data;
struct guest_iommu *iommu;
@@ -438,34 +438,30 @@ static void guest_iommu_process_command(void *data)
if ( !iommu->enabled )
return;
- head = iommu_get_rb_pointer(iommu->cmd_buffer.reg_head.lo);
- tail = iommu_get_rb_pointer(iommu->cmd_buffer.reg_tail.lo);
+ head = iommu->cmd_buffer.reg_head.lo;
+ tail = iommu->cmd_buffer.reg_tail.lo;
/* Tail pointer is rolled over by guest driver, value outside
* cmd_buffer_entries cause iommu disabled
*/
- if ( tail >= iommu->cmd_buffer.entries ||
- head >= iommu->cmd_buffer.entries )
+ if ( tail >= iommu->cmd_buffer.size || head >= iommu->cmd_buffer.size )
{
AMD_IOMMU_DEBUG("Error: guest iommu cmd buffer overflows\n");
guest_iommu_disable(iommu);
return;
}
- entries_per_page = PAGE_SIZE / sizeof(cmd_entry_t);
-
while ( head != tail )
{
int ret = 0;
cmd_mfn = guest_iommu_get_table_mfn(d,
reg_to_u64(iommu->cmd_buffer.reg_base),
- sizeof(cmd_entry_t), head);
+ head);
ASSERT(mfn_valid(_mfn(cmd_mfn)));
- cmd_base = map_domain_page(_mfn(cmd_mfn));
- cmd = cmd_base + head % entries_per_page;
+ cmd = map_domain_page(_mfn(cmd_mfn)) + (head & ~PAGE_MASK);
opcode = get_field_from_reg_u32(cmd->data[1],
IOMMU_CMD_OPCODE_MASK,
@@ -498,15 +494,16 @@ static void guest_iommu_process_command(void *data)
break;
}
- unmap_domain_page(cmd_base);
- if ( ++head >= iommu->cmd_buffer.entries )
+ unmap_domain_page(cmd);
+ head += sizeof(cmd_entry_t);
+ if ( head >= iommu->cmd_buffer.size )
head = 0;
if ( ret )
guest_iommu_disable(iommu);
}
/* Now shift cmd buffer head pointer */
- iommu_set_rb_pointer(&iommu->cmd_buffer.reg_head.lo, head);
+ iommu->cmd_buffer.reg_head.lo = head;
return;
}
@@ -672,23 +669,23 @@ static void guest_iommu_mmio_write64(struct guest_iommu
*iommu,
guest_iommu_write_ctrl(iommu, val);
break;
case IOMMU_CMD_BUFFER_HEAD_OFFSET:
- u64_to_reg(&iommu->cmd_buffer.reg_head, val);
+ iommu->cmd_buffer.reg_head.lo = val & IOMMU_RING_BUFFER_PTR_MASK;
break;
case IOMMU_CMD_BUFFER_TAIL_OFFSET:
- u64_to_reg(&iommu->cmd_buffer.reg_tail, val);
+ iommu->cmd_buffer.reg_tail.lo = val & IOMMU_RING_BUFFER_PTR_MASK;
tasklet_schedule(&iommu->cmd_buffer_tasklet);
break;
case IOMMU_EVENT_LOG_HEAD_OFFSET:
- u64_to_reg(&iommu->event_log.reg_head, val);
+ iommu->event_log.reg_head.lo = val & IOMMU_RING_BUFFER_PTR_MASK;
break;
case IOMMU_EVENT_LOG_TAIL_OFFSET:
- u64_to_reg(&iommu->event_log.reg_tail, val);
+ iommu->event_log.reg_tail.lo = val & IOMMU_RING_BUFFER_PTR_MASK;
break;
case IOMMU_PPR_LOG_HEAD_OFFSET:
- u64_to_reg(&iommu->ppr_log.reg_head, val);
+ iommu->ppr_log.reg_head.lo = val & IOMMU_RING_BUFFER_PTR_MASK;
break;
case IOMMU_PPR_LOG_TAIL_OFFSET:
- u64_to_reg(&iommu->ppr_log.reg_tail, val);
+ iommu->ppr_log.reg_tail.lo = val & IOMMU_RING_BUFFER_PTR_MASK;
break;
case IOMMU_STATUS_MMIO_OFFSET:
val &= IOMMU_STATUS_EVENT_LOG_OVERFLOW |
--
generated by git-patchbot for /home/xen/git/xen.git#staging
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