[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [V11 1/4] hw/i386: Introduce AMD IOMMU
From: |
Jan Kiszka |
Subject: |
Re: [Qemu-devel] [V11 1/4] hw/i386: Introduce AMD IOMMU |
Date: |
Sun, 22 May 2016 20:17:08 +0200 |
User-agent: |
Mozilla/5.0 (X11; U; Linux i686 (x86_64); de; rv:1.8.1.12) Gecko/20080226 SUSE/2.0.0.12-1.1 Thunderbird/2.0.0.12 Mnenhy/0.7.5.666 |
On 2016-05-22 20:12, Jan Kiszka wrote:
> On 2016-05-22 12:21, David Kiarie wrote:
>> +static void amdvi_page_walk(AMDVIAddressSpace *as, uint64_t *dte,
>> + IOMMUTLBEntry *ret, unsigned perms,
>> + hwaddr addr)
>> +{
>> + unsigned level, present, pte_perms, oldlevel;
>> + uint64_t pte = dte[0], pte_addr, page_mask;
>> +
>> + /* make sure the DTE has TV = 1 */
>> + if (pte & AMDVI_DEV_TRANSLATION_VALID) {
>> + level = get_pte_translation_mode(pte);
>> + if (level >= 7) {
>> + AMDVI_DPRINTF(MMU, "error: translation level 0x%"PRIu8 "
>> detected"
>> + " while translating 0x%"PRIx64, level, addr);
>> + return;
>> + }
>> + if (level == 0) {
>> + goto no_remap;
>> + }
>> +
>> + /* we are at the leaf page table or page table encodes a huge page
>> */
>> + while (level > 0) {
>> + pte_perms = amdvi_get_perms(pte);
>> + present = pte & 1;
>> + if (!present || perms != (perms & pte_perms)) {
>> + amdvi_page_fault(as->iommu_state, as->devfn, addr, perms);
>> + AMDVI_DPRINTF(CUSTOM, "error: page fault accessing virtual "
>> + "addr 0x%"PRIx64, addr);
>> + return;
>> + }
>> +
>> + /* go to the next lower level */
>> + pte_addr = pte & AMDVI_DEV_PT_ROOT_MASK;
>> + /* add offset and load pte */
>> + pte_addr += ((addr >> (3 + 9 * level)) & 0x1FF) << 3;
>> + pte = ldq_phys(&address_space_memory, pte_addr);
>
> I think this should be address_space_ldq_le. ldq_phys is for usage by
> CPUs only (and it breaks the build over master).
Correction: dma_memory_read, and then you need to do the byte-swapping
afterwards. Not the dma_memory_read may return an error if the address
points to something invalid. You will have to enable this (like a
non-present entry). See also the Intel IOMMU code.
Jan
signature.asc
Description: OpenPGP digital signature