On 8/17/24 8:34 AM, Andrew Jones wrote:
On Thu, Aug 01, 2024 at 12:43:24PM GMT, Daniel Henrique Barboza wrote:
From: Tomasz Jeznach <tjezn...@rivosinc.com>
The RISC-V IOMMU specification is now ratified as-per the RISC-V
international process. The latest frozen specifcation can be found at:
https://github.com/riscv-non-isa/riscv-iommu/releases/download/v1.0/riscv-iommu.pdf
Add the foundation of the device emulation for RISC-V IOMMU. It includes
support for s-stage (sv32, sv39, sv48, sv57 caps) and g-stage (sv32x4,
sv39x4, sv48x4, sv57x4 caps).
Other capabilities like ATS and DBG support will be added incrementally
in the next patches.
Co-developed-by: Sebastien Boeuf <s...@rivosinc.com>
Signed-off-by: Sebastien Boeuf <s...@rivosinc.com>
Signed-off-by: Tomasz Jeznach <tjezn...@rivosinc.com>
Signed-off-by: Daniel Henrique Barboza <dbarb...@ventanamicro.com>
---
(...)
+/* Redirect MSI write for given GPA. */
+static MemTxResult riscv_iommu_msi_write(RISCVIOMMUState *s,
+ RISCVIOMMUContext *ctx, uint64_t gpa, uint64_t data,
+ unsigned size, MemTxAttrs attrs)
+{
+ MemTxResult res;
+ dma_addr_t addr;
+ uint64_t intn;
+ uint32_t n190;
+ uint64_t pte[2];
+ int fault_type = RISCV_IOMMU_FQ_TTYPE_UADDR_WR;
+ int cause;
+
+ /* Interrupt File Number */
+ intn = _pext_u64(PPN_DOWN(gpa), ctx->msi_addr_mask);
+ if (intn >= 256) {
+ /* Interrupt file number out of range */
+ res = MEMTX_ACCESS_ERROR;
+ cause = RISCV_IOMMU_FQ_CAUSE_MSI_LOAD_FAULT;
+ goto err;
+ }
+
+ /* fetch MSI PTE */
+ addr = PPN_PHYS(get_field(ctx->msiptp, RISCV_IOMMU_DC_MSIPTP_PPN));
+ addr = addr | (intn * sizeof(pte));
+ res = dma_memory_read(s->target_as, addr, &pte, sizeof(pte),
+ MEMTXATTRS_UNSPECIFIED);
+ if (res != MEMTX_OK) {
+ if (res == MEMTX_DECODE_ERROR) {
+ cause = RISCV_IOMMU_FQ_CAUSE_MSI_PT_CORRUPTED;
+ } else {
+ cause = RISCV_IOMMU_FQ_CAUSE_MSI_LOAD_FAULT;
+ }
+ goto err;
+ }
+
+ le64_to_cpus(&pte[0]);
+ le64_to_cpus(&pte[1]);
+
+ if (!(pte[0] & RISCV_IOMMU_MSI_PTE_V) || (pte[0] & RISCV_IOMMU_MSI_PTE_C))
{
+ /*
+ * The spec mentions that: "If msipte.C == 1, then further
+ * processing to interpret the PTE is implementation
+ * defined.". We'll abort with cause = 262 for this
+ * case too.
+ */
+ res = MEMTX_ACCESS_ERROR;
+ cause = RISCV_IOMMU_FQ_CAUSE_MSI_INVALID;
+ goto err;
+ }
+
+ switch (get_field(pte[0], RISCV_IOMMU_MSI_PTE_M)) {
+ case RISCV_IOMMU_MSI_PTE_M_BASIC:
+ /* MSI Pass-through mode */
+ addr = PPN_PHYS(get_field(pte[0], RISCV_IOMMU_MSI_PTE_PPN));
+ addr = addr | (gpa & TARGET_PAGE_MASK);
I'm not sure what the idea was with this (maybe a misunderstanding of how
guest interrupt files get targeted?), but we shouldn't be modifying the
result of a translation with the input to that translation. It breaks
translations where guest imsic address bits don't strictly overlap host
imsic address bits and it allows the guest to access host memory it
shouldn't. The fix is just to remove the line.
I'll remove this line in v7. Thanks,
Daniel
Thanks,
drew
