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Re: [Qemu-devel] [V15 3/4] hw/i386: Introduce AMD IOMMU
From: |
Peter Xu |
Subject: |
Re: [Qemu-devel] [V15 3/4] hw/i386: Introduce AMD IOMMU |
Date: |
Tue, 9 Aug 2016 13:44:34 +0800 |
User-agent: |
Mutt/1.5.24 (2015-08-30) |
On Tue, Aug 02, 2016 at 11:39:06AM +0300, David Kiarie wrote:
[...]
> +/* invalidate internal caches for devid */
> +typedef struct QEMU_PACKED {
> +#ifdef HOST_WORDS_BIGENDIAN
> + uint64_t devid; /* device to invalidate */
> + uint64_t reserved_1:44;
> + uint64_t type:4; /* command type */
> +#else
> + uint64_t devid;
> + uint64_t reserved_1:44;
> + uint64_t type:4;
> +#endif /* __BIG_ENDIAN_BITFIELD */
Guess you forgot to reverse the order of fields in one of above block.
[...]
> +/* load adddress translation info for devid into translation cache */
> +typedef struct QEMU_PACKED {
> +#ifdef HOST_WORDS_BIGENDIAN
> + uint64_t type:4; /* command type */
> + uint64_t reserved_2:8;
> + uint64_t pasid_19_0:20;
> + uint64_t pfcount_7_0:8;
> + uint64_t reserved_1:8;
> + uint64_t devid; /* related devid */
> +#else
> + uint64_t devid;
> + uint64_t reserved_1:8;
> + uint64_t pfcount_7_0:8;
> + uint64_t pasid_19_0:20;
> + uint64_t reserved_2:8;
> + uint64_t type:4;
> +#endif /* __BIG_ENDIAN_BITFIELD */
For this one, "devid" looks like a 16 bits field?
[...]
> +/* issue a PCIe completion packet for devid */
> +typedef struct QEMU_PACKED {
> +#ifdef HOST_WORDS_BIGENDIAN
> + uint32_t devid; /* related devid */
> + uint32_t reserved_1;
> +#else
> + uint32_t reserved_1;
> + uint32_t devid;
> +#endif /* __BIG_ENDIAN_BITFIELD */
Here I am not sure we need this "#ifdef".
[...]
> +/* external write */
> +static void amdvi_writew(AMDVIState *s, hwaddr addr, uint16_t val)
> +{
> + uint16_t romask = lduw_le_p(&s->romask[addr]);
> + uint16_t w1cmask = lduw_le_p(&s->w1cmask[addr]);
> + uint16_t oldval = lduw_le_p(&s->mmior[addr]);
> + stw_le_p(&s->mmior[addr], (val & ~(val & w1cmask)) | (romask & oldval));
I think the above is problematic, e.g., what if we write 1 to one of
the romask while it's 0 originally? In that case, the RO bit will be
written to 1.
Maybe we need:
stw_le_p(&s->mmior[addr], ((oldval & romask) | (val & ~romask)) & \
(val & w1cmask));
Same question to the below two functions.
> +}
> +
> +static void amdvi_writel(AMDVIState *s, hwaddr addr, uint32_t val)
> +{
> + uint32_t romask = ldl_le_p(&s->romask[addr]);
> + uint32_t w1cmask = ldl_le_p(&s->w1cmask[addr]);
> + uint32_t oldval = ldl_le_p(&s->mmior[addr]);
> + stl_le_p(&s->mmior[addr], (val & ~(val & w1cmask)) | (romask & oldval));
> +}
> +
> +static void amdvi_writeq(AMDVIState *s, hwaddr addr, uint64_t val)
> +{
> + uint64_t romask = ldq_le_p(&s->romask[addr]);
> + uint64_t w1cmask = ldq_le_p(&s->w1cmask[addr]);
> + uint32_t oldval = ldq_le_p(&s->mmior[addr]);
> + stq_le_p(&s->mmior[addr], (val & ~(val & w1cmask)) | (romask & oldval));
> +}
> +
> +/* OR a 64-bit register with a 64-bit value */
> +static bool amdvi_orq(AMDVIState *s, hwaddr addr, uint64_t val)
Nit: This function name gives me an illusion that it's a write op, not
read. IMHO it'll be better we directly use amdvi_readq() for all the
callers of this function, which is more clear to me.
> +{
> + return amdvi_readq(s, addr) | val;
> +}
> +
> +/* OR a 64-bit register with a 64-bit value storing result in the register */
> +static void amdvi_orassignq(AMDVIState *s, hwaddr addr, uint64_t val)
> +{
> + amdvi_writeq_raw(s, addr, amdvi_readq(s, addr) | val);
> +}
> +
> +/* AND a 64-bit register with a 64-bit value storing result in the register
> */
> +static void amdvi_and_assignq(AMDVIState *s, hwaddr addr, uint64_t val)
Nit: the name is not matched with above:
amdvi_{or|and}assign[qw]
Though I would prefer:
amdvi_assign_[qw]_{or|and}
[...]
> +static void amdvi_log_event(AMDVIState *s, uint64_t *evt)
> +{
> + /* event logging not enabled */
> + if (!s->evtlog_enabled || amdvi_orq(s, AMDVI_MMIO_STATUS,
> + AMDVI_MMIO_STATUS_EVT_OVF)) {
> + return;
> + }
> +
> + /* event log buffer full */
> + if (s->evtlog_tail >= s->evtlog_len) {
> + amdvi_orassignq(s, AMDVI_MMIO_STATUS, AMDVI_MMIO_STATUS_EVT_OVF);
> + /* generate interrupt */
> + amdvi_generate_msi_interrupt(s);
> + return;
> + }
> +
> + if (dma_memory_write(&address_space_memory, s->evtlog_len +
> s->evtlog_tail,
> + &evt, AMDVI_EVENT_LEN)) {
Check with MEMTX_OK?
[...]
> +/*
> + * AMDVi event structure
> + * 0:15 -> DeviceID
> + * 55:63 -> event type + miscellaneous info
> + * 64:127 -> related address
> + */
> +static void amdvi_encode_event(uint64_t *evt, uint16_t devid, uint64_t addr,
> + uint16_t info)
> +{
> + amdvi_setevent_bits(evt, devid, 0, 16);
> + amdvi_setevent_bits(evt, info, 55, 8);
> + amdvi_setevent_bits(evt, addr, 63, 64);
^^
should here be 64?
Also, I am not sure whether we need this amdvi_setevent_bits() if it's
only used in this function. Though not a big problem for me.
> +}
> +/* log an error encountered page-walking
"during page-walking"
> + *
> + * @addr: virtual address in translation request
> + */
> +static void amdvi_page_fault(AMDVIState *s, uint16_t devid,
> + hwaddr addr, uint16_t info)
> +{
> + uint64_t evt[4];
> +
> + info |= AMDVI_EVENT_IOPF_I | AMDVI_EVENT_IOPF;
> + amdvi_encode_event(evt, devid, addr, info);
> + amdvi_log_event(s, evt);
> + pci_word_test_and_set_mask(s->pci.dev.config + PCI_STATUS,
> + PCI_STATUS_SIG_TARGET_ABORT);
Nit: maybe we can provide a function for setting this bit.
[...]
> +static void amdvi_update_iotlb(AMDVIState *s, uint16_t devid,
> + uint64_t gpa, IOMMUTLBEntry to_cache,
> + uint16_t domid)
> +{
> + AMDVIIOTLBEntry *entry = g_malloc(sizeof(*entry));
> + uint64_t *key = g_malloc(sizeof(key));
> + uint64_t gfn = gpa >> AMDVI_PAGE_SHIFT_4K;
> +
> + /* don't cache erroneous translations */
> + if (to_cache.perm != IOMMU_NONE) {
> + trace_amdvi_cache_update(domid, PCI_BUS_NUM(devid), PCI_SLOT(devid),
> + PCI_FUNC(devid), gpa, to_cache.translated_addr);
> +
> + if (g_hash_table_size(s->iotlb) >= AMDVI_IOTLB_MAX_SIZE) {
> + trace_amdvi_iotlb_reset();
We'd better put this trace into amdvi_iotlb_reset().
> + amdvi_iotlb_reset(s);
> + }
> +
> + entry->gfn = gfn;
> + entry->domid = domid;
> + entry->perms = to_cache.perm;
> + entry->translated_addr = to_cache.translated_addr;
> + entry->page_mask = to_cache.addr_mask;
> + *key = gfn | ((uint64_t)(devid) << AMDVI_DEVID_SHIFT);
> + g_hash_table_replace(s->iotlb, key, entry);
> + }
> +}
> +
> +static void amdvi_completion_wait(AMDVIState *s, CMDCompletionWait *wait)
> +{
> + /* pad the last 3 bits */
> + hwaddr addr = cpu_to_le64(wait->store_addr << 3);
Is this correct? IMO it should be:
hwaddr addr = le64_to_cpu(wait->store_addr) << 3;
> + uint64_t data = cpu_to_le64(wait->store_data);
Maybe:
uint64_t data = le64_to_cpu(wait->store_data);
?
> +
> + if (wait->reserved) {
> + amdvi_log_illegalcom_error(s, wait->type, s->cmdbuf +
> s->cmdbuf_head);
> + }
> +
> + if (wait->completion_store) {
> + if (dma_memory_write(&address_space_memory, addr, &data,
> + AMDVI_COMPLETION_DATA_SIZE))
> + {
Left bracket is better moved upward to follow the coding style.
> + trace_amdvi_completion_wait_fail(addr);
> + }
> + }
Thanks,
-- peterx
- [Qemu-devel] [V15 0/4] AMD IOMMU, David Kiarie, 2016/08/02
- [Qemu-devel] [V15 1/4] hw/pci: Prepare for AMD IOMMU, David Kiarie, 2016/08/02
- [Qemu-devel] [V15 2/4] hw/i386/trace-events: Add AMD IOMMU trace events, David Kiarie, 2016/08/02
- [Qemu-devel] [V15 4/4] hw/i386: AMD IOMMU IVRS table, David Kiarie, 2016/08/02
- [Qemu-devel] [V15 3/4] hw/i386: Introduce AMD IOMMU, David Kiarie, 2016/08/02
- Re: [Qemu-devel] [V15 3/4] hw/i386: Introduce AMD IOMMU, Peter Xu, 2016/08/09
- Re: [Qemu-devel] [V15 3/4] hw/i386: Introduce AMD IOMMU, David Kiarie, 2016/08/10
- Re: [Qemu-devel] [V15 3/4] hw/i386: Introduce AMD IOMMU, David Kiarie, 2016/08/09
- Re: [Qemu-devel] [V15 3/4] hw/i386: Introduce AMD IOMMU, Peter Xu, 2016/08/09
Re: [Qemu-devel] [V15 3/4] hw/i386: Introduce AMD IOMMU, Valentine Sinitsyn, 2016/08/11