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Re: [PATCH v4 4/7] Convert 'info tlb' to use generic iterator.
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [PATCH v4 4/7] Convert 'info tlb' to use generic iterator. |
Date: |
Sat, 27 Jul 2024 20:47:56 +0000 |
User-agent: |
Mutt/2.2.12 (2023-09-09) |
* Don Porter (porter@cs.unc.edu) wrote:
> 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:
This surprises me from the title; the title made me think
this was a change purely to the implementation.
> (qemu) info tlb
> Info guest TLB (guest virtual to guest physical):
It's a shame that the code that prints this has no way to know the column
widths,
since it would be nice to have:
guest virt guest phys ???????????
> 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):
Do you actually want this to happen in the same operation, or do you
want info tlb -h (e.g.) to get the host info?
> 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++) {
It's nice to see all this hairy code disappearing.
> - 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);
Do we need that? It's a pretty arbitrary limit these days.
> - 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.
(What happens if the guest is using huge pages inside the guest?)
> + */
> + 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");
I wouldn't bother saying ' Internal error'.
> 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
>
--
-----Open up your eyes, open up your mind, open up your code -------
/ Dr. David Alan Gilbert | Running GNU/Linux | Happy \
\ dave @ treblig.org | | In Hex /
\ _________________________|_____ http://www.treblig.org |_______/
- [PATCH v4 0/7] Rework x86 page table walks, Don Porter, 2024/07/22
- [PATCH v4 1/7] Code motion: expose some TCG definitions for page table walk consolidation., Don Porter, 2024/07/22
- [PATCH v4 2/7] Import vmcs12 definition from Linux/KVM, Don Porter, 2024/07/22
- [PATCH v4 4/7] Convert 'info tlb' to use generic iterator., Don Porter, 2024/07/22
- Re: [PATCH v4 4/7] Convert 'info tlb' to use generic iterator.,
Dr. David Alan Gilbert <=
- [PATCH v4 5/7] Convert 'info mem' to use generic iterator, Don Porter, 2024/07/22
- [PATCH v4 3/7] Add an "info pg" command that prints the current page tables, Don Porter, 2024/07/22
- [PATCH v4 6/7] Convert x86_cpu_get_memory_mapping() to use generic iterators, Don Porter, 2024/07/22
- [PATCH v4 7/7] Convert x86_mmu_translate() to use common code., Don Porter, 2024/07/22
- Re: [PATCH v4 0/7] Rework x86 page table walks, Richard Henderson, 2024/07/23