[PATCH 1/3] ppc: Check partition and process table alignment

[Leandro Lupori]

Check if partition and process tables are properly aligned, in
their size, according to PowerISA 3.1B, Book III 6.7.6 programming
note. Hardware and KVM also raise an exception in these cases.

Signed-off-by: Leandro Lupori <leandro.lupori@eldorado.org.br>
---
 hw/ppc/spapr.c             |  5 +++++
 hw/ppc/spapr_hcall.c       |  9 +++++++++
 target/ppc/mmu-book3s-v3.c |  5 +++++
 target/ppc/mmu-radix64.c   | 17 +++++++++++++----
 4 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index fd4942e881..4b1f346087 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -1329,6 +1329,11 @@ static bool spapr_get_pate(PPCVirtualHypervisor *vhyp, 
PowerPCCPU *cpu,
         patb = spapr->nested_ptcr & PTCR_PATB;
         pats = spapr->nested_ptcr & PTCR_PATS;
 
+        /* Check if partition table is properly aligned */
+        if (patb & MAKE_64BIT_MASK(0, pats + 12)) {
+            return false;
+        }
+
         /* Calculate number of entries */
         pats = 1ull << (pats + 12 - 4);
         if (pats <= lpid) {
diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
index d761a7d0c3..2a73ba8a1d 100644
--- a/hw/ppc/spapr_hcall.c
+++ b/hw/ppc/spapr_hcall.c
@@ -920,6 +920,7 @@ static target_ulong h_register_process_table(PowerPCCPU 
*cpu,
     target_ulong page_size = args[2];
     target_ulong table_size = args[3];
     target_ulong update_lpcr = 0;
+    target_ulong table_byte_size;
     uint64_t cproc;
 
     if (flags & ~FLAGS_MASK) { /* Check no reserved bits are set */
@@ -927,6 +928,14 @@ static target_ulong h_register_process_table(PowerPCCPU 
*cpu,
     }
     if (flags & FLAG_MODIFY) {
         if (flags & FLAG_REGISTER) {
+            /* Check process table alignment */
+            table_byte_size = 1ULL << (table_size + 12);
+            if (proc_tbl & (table_byte_size - 1)) {
+                qemu_log_mask(LOG_GUEST_ERROR,
+                    "%s: process table not properly aligned: "
+                    "proc_tbl 0x%lx proc_tbl_size 0x%lx\n",
+                    __func__, proc_tbl, table_byte_size);
+            }
             if (flags & FLAG_RADIX) { /* Register new RADIX process table */
                 if (proc_tbl & 0xfff || proc_tbl >> 60) {
                     return H_P2;
diff --git a/target/ppc/mmu-book3s-v3.c b/target/ppc/mmu-book3s-v3.c
index f4985bae78..c8f69b3df9 100644
--- a/target/ppc/mmu-book3s-v3.c
+++ b/target/ppc/mmu-book3s-v3.c
@@ -28,6 +28,11 @@ bool ppc64_v3_get_pate(PowerPCCPU *cpu, target_ulong lpid, 
ppc_v3_pate_t *entry)
     uint64_t patb = cpu->env.spr[SPR_PTCR] & PTCR_PATB;
     uint64_t pats = cpu->env.spr[SPR_PTCR] & PTCR_PATS;
 
+    /* Check if partition table is properly aligned */
+    if (patb & MAKE_64BIT_MASK(0, pats + 12)) {
+        return false;
+    }
+
     /* Calculate number of entries */
     pats = 1ull << (pats + 12 - 4);
     if (pats <= lpid) {
diff --git a/target/ppc/mmu-radix64.c b/target/ppc/mmu-radix64.c
index 21ac958e48..9a8a2e2875 100644
--- a/target/ppc/mmu-radix64.c
+++ b/target/ppc/mmu-radix64.c
@@ -383,7 +383,7 @@ static int ppc_radix64_process_scoped_xlate(PowerPCCPU *cpu,
 {
     CPUState *cs = CPU(cpu);
     CPUPPCState *env = &cpu->env;
-    uint64_t offset, size, prtbe_addr, prtbe0, base_addr, nls, index, pte;
+    uint64_t offset, size, prtb, prtbe_addr, prtbe0, base_addr, nls, index, 
pte;
     int fault_cause = 0, h_page_size, h_prot;
     hwaddr h_raddr, pte_addr;
     int ret;
@@ -393,9 +393,18 @@ static int ppc_radix64_process_scoped_xlate(PowerPCCPU 
*cpu,
                   __func__, access_str(access_type),
                   eaddr, mmu_idx, pid);
 
+    prtb = (pate.dw1 & PATE1_R_PRTB);
+    size = 1ULL << ((pate.dw1 & PATE1_R_PRTS) + 12);
+    if (prtb & (size - 1)) {
+        /* Process Table not properly aligned */
+        if (guest_visible) {
+            ppc_radix64_raise_si(cpu, access_type, eaddr, DSISR_R_BADCONFIG);
+        }
+        return 1;
+    }
+
     /* Index Process Table by PID to Find Corresponding Process Table Entry */
     offset = pid * sizeof(struct prtb_entry);
-    size = 1ULL << ((pate.dw1 & PATE1_R_PRTS) + 12);
     if (offset >= size) {
         /* offset exceeds size of the process table */
         if (guest_visible) {
@@ -403,7 +412,7 @@ static int ppc_radix64_process_scoped_xlate(PowerPCCPU *cpu,
         }
         return 1;
     }
-    prtbe_addr = (pate.dw1 & PATE1_R_PRTB) + offset;
+    prtbe_addr = prtb + offset;
 
     if (vhyp_flat_addressing(cpu)) {
         prtbe0 = ldq_phys(cs->as, prtbe_addr);
@@ -568,7 +577,7 @@ static bool ppc_radix64_xlate_impl(PowerPCCPU *cpu, vaddr 
eaddr,
         return false;
     }
 
-    /* Get Process Table */
+    /* Get Partition Table */
     if (cpu->vhyp) {
         PPCVirtualHypervisorClass *vhc;
         vhc = PPC_VIRTUAL_HYPERVISOR_GET_CLASS(cpu->vhyp);
-- 
2.25.1