[PATCH v4 4/7] Convert 'info tlb' to use generic iterator.

[Don Porter]

If the the guest is using nested page tables, change the output format
slightly, to first show guest virtual to guest physical, then guest
physical to host physical, as below:

(qemu) info tlb
Info guest TLB (guest virtual to guest physical):
0000008000800000: 000000000076a000  -------U-P
0000008000801000: 000000000076b000  -------U-P
0000008000802000: 000000000076c000  -------U-P
0000008000803000: 000000000076d000  -------U-P
[...]
0000008004ffd000: 0000000000ffd000  --------WP
0000008004ffe000: 0000000000ffe000  --------WP
0000008004fff000: 0000000000fff000  --------WP
Info host TLB, (guest physical to host physical):
0000000000001000: 0000000001b20000  ----XWR
0000000000002000: 0000000001b21000  ----XWR
0000000000003000: 0000000001b22000  ----XWR
0000000000004000: 0000000001b23000  ----XWR
0000000000005000: 0000000001b24000  ----XWR
[...]

Signed-off-by: Don Porter <porter@cs.unc.edu>
---
 include/hw/core/sysemu-cpu-ops.h |   7 +
 target/i386/cpu.c                |   1 +
 target/i386/cpu.h                |   2 +
 target/i386/monitor.c            | 233 +++++++++----------------------
 4 files changed, 75 insertions(+), 168 deletions(-)

diff --git a/include/hw/core/sysemu-cpu-ops.h b/include/hw/core/sysemu-cpu-ops.h
index d0e939def8..083df4717c 100644
--- a/include/hw/core/sysemu-cpu-ops.h
+++ b/include/hw/core/sysemu-cpu-ops.h
@@ -225,6 +225,13 @@ typedef struct SysemuCPUOps {
     bool (*mon_flush_page_print_state)(CPUState *cs,
                                        struct mem_print_state *state);
 
+    /**
+     * @mon_print_pte: Hook called by the monitor to print a page
+     * table entry at address addr, with contents pte.
+     */
+    void (*mon_print_pte) (CPUState *cs, GString *buf, hwaddr addr,
+                           hwaddr pte, uint64_t prot, int mmu_idx);
+
 } SysemuCPUOps;
 
 int compressing_iterator(CPUState *cs, void *data, DecodedPTE *pte,
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index ec419e0ef0..030198497a 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -8388,6 +8388,7 @@ static const struct SysemuCPUOps i386_sysemu_ops = {
     .mon_init_page_table_iterator = &x86_mon_init_page_table_iterator,
     .mon_info_pg_print_header = &x86_mon_info_pg_print_header,
     .mon_flush_page_print_state = &x86_mon_flush_print_pg_state,
+    .mon_print_pte = &x86_mon_print_pte,
 };
 #endif
 
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index 4e5877f41d..413c743c1a 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -2264,6 +2264,8 @@ bool x86_mon_init_page_table_iterator(CPUState *cpu, 
GString *buf, int mmu_idx,
                                       struct mem_print_state *state);
 void x86_mon_info_pg_print_header(struct mem_print_state *state);
 bool x86_mon_flush_print_pg_state(CPUState *cs, struct mem_print_state *state);
+void x86_mon_print_pte(CPUState *cs, GString *out_buf, hwaddr addr,
+                       hwaddr child, uint64_t prot, int mmu_idx);
 bool x86_ptw_translate(CPUState *cs, vaddr vaddress, hwaddr *hpa,
                        bool debug, int mmu_idx, bool user_access,
                        const MMUAccessType access_type, uint64_t *page_size,
diff --git a/target/i386/monitor.c b/target/i386/monitor.c
index 8ef92e7c42..d88347684b 100644
--- a/target/i386/monitor.c
+++ b/target/i386/monitor.c
@@ -224,201 +224,98 @@ static hwaddr addr_canonical(CPUArchState *env, hwaddr 
addr)
     return addr;
 }
 
-static void print_pte(Monitor *mon, CPUArchState *env, hwaddr addr,
-                      hwaddr pte, hwaddr mask)
+void x86_mon_print_pte(CPUState *cs, GString *out_buf, hwaddr addr,
+                       hwaddr child, uint64_t prot, int mmu_idx)
 {
+    CPUX86State *env = cpu_env(cs);
+    g_autoptr(GString) buf = g_string_new("");
+
     addr = addr_canonical(env, addr);
 
-    monitor_printf(mon, HWADDR_FMT_plx ": " HWADDR_FMT_plx
-                   " %c%c%c%c%c%c%c%c%c\n",
-                   addr,
-                   pte & mask,
-                   pte & PG_NX_MASK ? 'X' : '-',
-                   pte & PG_GLOBAL_MASK ? 'G' : '-',
-                   pte & PG_PSE_MASK ? 'P' : '-',
-                   pte & PG_DIRTY_MASK ? 'D' : '-',
-                   pte & PG_ACCESSED_MASK ? 'A' : '-',
-                   pte & PG_PCD_MASK ? 'C' : '-',
-                   pte & PG_PWT_MASK ? 'T' : '-',
-                   pte & PG_USER_MASK ? 'U' : '-',
-                   pte & PG_RW_MASK ? 'W' : '-');
-}
+    g_string_append_printf(buf, HWADDR_FMT_plx ": " HWADDR_FMT_plx " ",
+                           addr, child);
 
-static void tlb_info_32(Monitor *mon, CPUArchState *env)
-{
-    unsigned int l1, l2;
-    uint32_t pgd, pde, pte;
+    g_string_append_printf(buf, " %s", pg_bits(cs, prot, mmu_idx));
 
-    pgd = env->cr[3] & ~0xfff;
-    for(l1 = 0; l1 < 1024; l1++) {
-        cpu_physical_memory_read(pgd + l1 * 4, &pde, 4);
-        pde = le32_to_cpu(pde);
-        if (pde & PG_PRESENT_MASK) {
-            if ((pde & PG_PSE_MASK) && (env->cr[4] & CR4_PSE_MASK)) {
-                /* 4M pages */
-                print_pte(mon, env, (l1 << 22), pde, ~((1 << 21) - 1));
-            } else {
-                for(l2 = 0; l2 < 1024; l2++) {
-                    cpu_physical_memory_read((pde & ~0xfff) + l2 * 4, &pte, 4);
-                    pte = le32_to_cpu(pte);
-                    if (pte & PG_PRESENT_MASK) {
-                        print_pte(mon, env, (l1 << 22) + (l2 << 12),
-                                  pte & ~PG_PSE_MASK,
-                                  ~0xfff);
-                    }
-                }
-            }
-        }
-    }
-}
-
-static void tlb_info_pae32(Monitor *mon, CPUArchState *env)
-{
-    unsigned int l1, l2, l3;
-    uint64_t pdpe, pde, pte;
-    uint64_t pdp_addr, pd_addr, pt_addr;
+    /* Trim line to fit screen */
+    g_string_truncate(buf, 79);
 
-    pdp_addr = env->cr[3] & ~0x1f;
-    for (l1 = 0; l1 < 4; l1++) {
-        cpu_physical_memory_read(pdp_addr + l1 * 8, &pdpe, 8);
-        pdpe = le64_to_cpu(pdpe);
-        if (pdpe & PG_PRESENT_MASK) {
-            pd_addr = pdpe & 0x3fffffffff000ULL;
-            for (l2 = 0; l2 < 512; l2++) {
-                cpu_physical_memory_read(pd_addr + l2 * 8, &pde, 8);
-                pde = le64_to_cpu(pde);
-                if (pde & PG_PRESENT_MASK) {
-                    if (pde & PG_PSE_MASK) {
-                        /* 2M pages with PAE, CR4.PSE is ignored */
-                        print_pte(mon, env, (l1 << 30) + (l2 << 21), pde,
-                                  ~((hwaddr)(1 << 20) - 1));
-                    } else {
-                        pt_addr = pde & 0x3fffffffff000ULL;
-                        for (l3 = 0; l3 < 512; l3++) {
-                            cpu_physical_memory_read(pt_addr + l3 * 8, &pte, 
8);
-                            pte = le64_to_cpu(pte);
-                            if (pte & PG_PRESENT_MASK) {
-                                print_pte(mon, env, (l1 << 30) + (l2 << 21)
-                                          + (l3 << 12),
-                                          pte & ~PG_PSE_MASK,
-                                          ~(hwaddr)0xfff);
-                            }
-                        }
-                    }
-                }
-            }
-        }
-    }
+    g_string_append_printf(out_buf, "%s\n", buf->str);
 }
 
-#ifdef TARGET_X86_64
-static void tlb_info_la48(Monitor *mon, CPUArchState *env,
-        uint64_t l0, uint64_t pml4_addr)
+static
+int mem_print_tlb(CPUState *cs, void *data, DecodedPTE *pte, int height,
+                  int offset, int mmu_idx, const PageTableLayout *layout)
 {
-    uint64_t l1, l2, l3, l4;
-    uint64_t pml4e, pdpe, pde, pte;
-    uint64_t pdp_addr, pd_addr, pt_addr;
-
-    for (l1 = 0; l1 < 512; l1++) {
-        cpu_physical_memory_read(pml4_addr + l1 * 8, &pml4e, 8);
-        pml4e = le64_to_cpu(pml4e);
-        if (!(pml4e & PG_PRESENT_MASK)) {
-            continue;
-        }
-
-        pdp_addr = pml4e & 0x3fffffffff000ULL;
-        for (l2 = 0; l2 < 512; l2++) {
-            cpu_physical_memory_read(pdp_addr + l2 * 8, &pdpe, 8);
-            pdpe = le64_to_cpu(pdpe);
-            if (!(pdpe & PG_PRESENT_MASK)) {
-                continue;
-            }
+    struct mem_print_state *state = (struct mem_print_state *) data;
+    CPUClass *cc = CPU_GET_CLASS(cs);
 
-            if (pdpe & PG_PSE_MASK) {
-                /* 1G pages, CR4.PSE is ignored */
-                print_pte(mon, env, (l0 << 48) + (l1 << 39) + (l2 << 30),
-                        pdpe, 0x3ffffc0000000ULL);
-                continue;
-            }
-
-            pd_addr = pdpe & 0x3fffffffff000ULL;
-            for (l3 = 0; l3 < 512; l3++) {
-                cpu_physical_memory_read(pd_addr + l3 * 8, &pde, 8);
-                pde = le64_to_cpu(pde);
-                if (!(pde & PG_PRESENT_MASK)) {
-                    continue;
-                }
+    cc->sysemu_ops->mon_print_pte(cs, state->buf, pte->bits_translated,
+                                  pte->child, pte->prot, mmu_idx);
 
-                if (pde & PG_PSE_MASK) {
-                    /* 2M pages, CR4.PSE is ignored */
-                    print_pte(mon, env, (l0 << 48) + (l1 << 39) + (l2 << 30) +
-                            (l3 << 21), pde, 0x3ffffffe00000ULL);
-                    continue;
-                }
-
-                pt_addr = pde & 0x3fffffffff000ULL;
-                for (l4 = 0; l4 < 512; l4++) {
-                    cpu_physical_memory_read(pt_addr
-                            + l4 * 8,
-                            &pte, 8);
-                    pte = le64_to_cpu(pte);
-                    if (pte & PG_PRESENT_MASK) {
-                        print_pte(mon, env, (l0 << 48) + (l1 << 39) +
-                                (l2 << 30) + (l3 << 21) + (l4 << 12),
-                                pte & ~PG_PSE_MASK, 0x3fffffffff000ULL);
-                    }
-                }
-            }
-        }
-    }
+    return 0;
 }
 
-static void tlb_info_la57(Monitor *mon, CPUArchState *env)
+static
+void helper_hmp_info_tlb(CPUState *cs, Monitor *mon, int mmu_idx)
 {
-    uint64_t l0;
-    uint64_t pml5e;
-    uint64_t pml5_addr;
+    struct mem_print_state state;
+    g_autoptr(GString) buf = g_string_new("");
+    CPUClass *cc = CPU_GET_CLASS(cs);
 
-    pml5_addr = env->cr[3] & 0x3fffffffff000ULL;
-    for (l0 = 0; l0 < 512; l0++) {
-        cpu_physical_memory_read(pml5_addr + l0 * 8, &pml5e, 8);
-        pml5e = le64_to_cpu(pml5e);
-        if (pml5e & PG_PRESENT_MASK) {
-            tlb_info_la48(mon, env, l0, pml5e & 0x3fffffffff000ULL);
-        }
+    if (!cc->sysemu_ops->mon_init_page_table_iterator(cs, buf, mmu_idx,
+                                                      &state)) {
+        monitor_printf(mon, "Unable to initialize page table iterator\n");
+        return;
     }
+
+    /**
+     * 'info tlb' visits only leaf PTEs marked present.
+     * It does not check other protection bits.
+     */
+    for_each_pte(cs, &mem_print_tlb, &state, false, false, false,  mmu_idx);
+
+    monitor_printf(mon, "%s", buf->str);
 }
-#endif /* TARGET_X86_64 */
 
 void hmp_info_tlb(Monitor *mon, const QDict *qdict)
 {
-    CPUArchState *env;
+    CPUState *cs = mon_get_cpu(mon);
+    bool nested;
 
-    env = mon_get_cpu_env(mon);
-    if (!env) {
-        monitor_printf(mon, "No CPU available\n");
+    if (!cs) {
+        monitor_printf(mon, "Unable to get CPUState.  Internal error\n");
         return;
     }
 
-    if (!(env->cr[0] & CR0_PG_MASK)) {
+    if (!cpu_paging_enabled(cs, 0)) {
         monitor_printf(mon, "PG disabled\n");
         return;
     }
-    if (env->cr[4] & CR4_PAE_MASK) {
-#ifdef TARGET_X86_64
-        if (env->hflags & HF_LMA_MASK) {
-            if (env->cr[4] & CR4_LA57_MASK) {
-                tlb_info_la57(mon, env);
-            } else {
-                tlb_info_la48(mon, env, 0, env->cr[3] & 0x3fffffffff000ULL);
-            }
-        } else
-#endif
-        {
-            tlb_info_pae32(mon, env);
-        }
-    } else {
-        tlb_info_32(mon, env);
+
+    CPUClass *cc = CPU_GET_CLASS(cs);
+
+    if (!cc->sysemu_ops->mon_print_pte
+        || !cc->sysemu_ops->mon_init_page_table_iterator) {
+        monitor_printf(mon, "Info tlb unsupported on this ISA\n");
+        return;
+    }
+
+    nested = cpu_paging_enabled(cs, 1);
+
+    if (nested) {
+        monitor_printf(mon,
+                       "Info guest TLB (guest virtual to guest physical):\n");
+    }
+
+    helper_hmp_info_tlb(cs, mon, 0);
+
+    if (nested) {
+        monitor_printf(mon,
+                       "Info host TLB, (guest physical to host physical):\n");
+
+        helper_hmp_info_tlb(cs, mon, 1);
+
     }
 }
 
-- 
2.34.1