/*
* vmware_guestdump.c
*
* Copyright (c) 2020 VMware, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* Author: Alexey Makhalov <amakhalov@vmware.com>
*/
#include "defs.h"
#include "vmware_vmss.h"
#define LOGPRX "vmw: "
#define GUESTDUMP_VERSION 4
#define GUESTDUMP_MAGIC1 1
#define GUESTDUMP_MAGIC2 0
struct guestdumpheader {
uint32_t version;
uint32_t num_vcpus;
uint8_t magic1;
uint8_t reserved1;
uint32_t cpu_vendor;
uint64_t magic2;
uint64_t last_addr;
uint64_t memsize_in_pages;
uint32_t reserved2;
uint32_t mem_holes;
struct memhole {
uint64_t ppn;
uint64_t pages;
} holes[2];
} __attribute__((packed));
struct vcpu_state {
uint32_t cr0;
uint64_t cr2;
uint64_t cr3;
uint64_t cr4;
uint64_t reserved1[10];
uint64_t idt_base;
uint16_t reserved2[21];
struct x86_64_pt_regs {
uint64_t r15;
uint64_t r14;
uint64_t r13;
uint64_t r12;
uint64_t rbp;
uint64_t rbx;
uint64_t r11;
uint64_t r10;
uint64_t r9;
uint64_t r8;
uint64_t rax;
uint64_t rcx;
uint64_t rdx;
uint64_t rsi;
uint64_t rdi;
uint64_t orig_rax;
uint64_t rip;
uint64_t cs;
uint64_t eflags;
uint64_t rsp;
uint64_t ss;
} regs64;
uint8_t reserved3[65];
} __attribute__((packed));
/*
* vmware_guestdump is extension to vmware_vmss with ability to debug
* debug.guest and debug.vmem files.
*
* debug.guest.gz and debug.vmem.gz can be obtained using following
* .vmx options from VM running in debug mode:
* monitor.mini-suspend_on_panic = TRUE
* monitor.suspend_on_triplefault = TRUE
*
* guestdump (debug.guest) is simplified version of *.vmss which does
* not contain full VM state, but minimal guest state, such as memory
* layout and CPUs state, needed for debugger. is_vmware_guestdump()
* and vmware_guestdump_init() functions parse guestdump header and
* populate vmss data structure (from vmware_vmss.c). As result, all
* handlers (except mempry_dump) from vmware_vmss.c can be reused.
*
* debug.guest does not have dedicated header magic or signature for
* its format. To probe debug.guest we need to perform header fields
* and file size validity. In addition, check for the filename
* extension, which must be ".guest".
*/
int
is_vmware_guestdump(char *filename)
{
struct guestdumpheader hdr;
FILE *fp;
uint64_t filesize, holes_sum = 0;
int i;
if (strcmp(filename + strlen(filename) - 6, ".guest"))
return FALSE;
if ((fp = fopen(filename, "r")) == NULL) {
error(INFO, LOGPRX"Failed to open '%s': [Error %d] %s\n",
filename, errno, strerror(errno));
return FALSE;
}
if (fread(&hdr, sizeof(struct guestdumpheader), 1, fp) != 1) {
error(INFO, LOGPRX"Failed to read '%s': [Error %d] %s\n",
filename, errno, strerror(errno));
fclose(fp);
return FALSE;
}
if (fseek(fp, 0L, SEEK_END) == -1) {
error(INFO, LOGPRX"Failed to fseek '%s': [Error %d] %s\n",
filename, errno, strerror(errno));
fclose(fp);
return FALSE;
}
filesize = ftell(fp);
fclose(fp);
if (hdr.mem_holes > 2)
goto unrecognized;
for (i = 0; i < hdr.mem_holes; i++) {
/* hole start page */
vmss.regions[i].startpagenum = hdr.holes[i].ppn;
/* hole end page */
vmss.regions[i].startppn = hdr.holes[i].ppn + hdr.holes[i].pages;
holes_sum += hdr.holes[i].pages;
}
if (hdr.version != GUESTDUMP_VERSION ||
hdr.magic1 != GUESTDUMP_MAGIC1 ||
hdr.magic2 != GUESTDUMP_MAGIC2 ||
(hdr.last_addr + 1) != ((hdr.memsize_in_pages + holes_sum) << VMW_PAGE_SHIFT) ||
filesize != sizeof(struct guestdumpheader) +
hdr.num_vcpus * (sizeof (struct vcpu_state) + VMW_PAGE_SIZE))
goto unrecognized;
vmss.memsize = hdr.memsize_in_pages << VMW_PAGE_SHIFT;
vmss.regionscount = hdr.mem_holes + 1;
vmss.memoffset = 0;
vmss.num_vcpus = hdr.num_vcpus;
return TRUE;
unrecognized:
if (CRASHDEBUG(1))
error(INFO, LOGPRX"Unrecognized debug.guest file.\n");
return FALSE;
}
int
vmware_guestdump_init(char *filename, FILE *ofp)
{
FILE *fp = NULL;
int i, result = TRUE;
char *vmem_filename = NULL;
struct vcpu_state vs;
char *p;
if (!machine_type("X86") && !machine_type("X86_64")) {
error(INFO,
LOGPRX"Invalid or unsupported host architecture for .vmss file: %s\n",
MACHINE_TYPE);
result = FALSE;
goto exit;
}
if ((fp = fopen(filename, "r")) == NULL) {
error(INFO, LOGPRX"Failed to open '%s': [Error %d] %s\n",
filename, errno, strerror(errno));
result = FALSE;
goto exit;
}
if (fseek(fp, sizeof(struct guestdumpheader), SEEK_SET) == -1) {
error(INFO, LOGPRX"Failed to fseek '%s': [Error %d] %s\n",
filename, errno, strerror(errno));
result = FALSE;
goto exit;
}
vmss.vcpu_regs = malloc(vmss.num_vcpus * sizeof(uint32_t));
vmss.regs64 = calloc(vmss.num_vcpus, sizeof(void *));
if (!vmss.vcpu_regs || !vmss.regs64) {
error(INFO, LOGPRX"Failed to allocate memory\n");
result = FALSE;
goto exit;
}
for (i = 0; i < vmss.num_vcpus; i++) {
if (fread(&vs, sizeof(struct vcpu_state), 1, fp) != 1) {
error(INFO, LOGPRX"Failed to read '%s': [Error %d] %s\n",
filename, errno, strerror(errno));
result = FALSE;
goto exit;
}
vmss.regs64[i] = calloc(1, sizeof(vmssregs64));
if (!vmss.regs64[i]) {
error(INFO, LOGPRX"Failed to allocate memory\n");
result = FALSE;
goto exit;
}
vmss.vcpu_regs[i] = 0;
vmss.regs64[i]->rax = vs.regs64.rax;
vmss.regs64[i]->rcx = vs.regs64.rcx;
vmss.regs64[i]->rdx = vs.regs64.rdx;
vmss.regs64[i]->rbx = vs.regs64.rbx;
vmss.regs64[i]->rbp = vs.regs64.rbp;
vmss.regs64[i]->rsp = vs.regs64.rsp;
vmss.regs64[i]->rsi = vs.regs64.rsi;
vmss.regs64[i]->rdi = vs.regs64.rdi;
vmss.regs64[i]->r8 = vs.regs64.r8;
vmss.regs64[i]->r9 = vs.regs64.r9;
vmss.regs64[i]->r10 = vs.regs64.r10;
vmss.regs64[i]->r11 = vs.regs64.r11;
vmss.regs64[i]->r12 = vs.regs64.r12;
vmss.regs64[i]->r13 = vs.regs64.r13;
vmss.regs64[i]->r14 = vs.regs64.r14;
vmss.regs64[i]->r15 = vs.regs64.r15;
vmss.regs64[i]->idtr = vs.idt_base;
vmss.regs64[i]->cr[0] = vs.cr0;
vmss.regs64[i]->cr[2] = vs.cr2;
vmss.regs64[i]->cr[3] = vs.cr3;
vmss.regs64[i]->cr[4] = vs.cr4;
vmss.regs64[i]->rip = vs.regs64.rip;
vmss.regs64[i]->rflags = vs.regs64.eflags;
vmss.vcpu_regs[i] = REGS_PRESENT_ALL;
}
vmem_filename = strdup(filename);
p = vmem_filename + strlen(vmem_filename) - 5;
if (strcmp(p, "guest") != 0) {
result = FALSE;
goto exit;
}
strcpy(p, "vmem");
fprintf(ofp, LOGPRX"Open the companion vmem file: %s\n", vmem_filename);
if ((vmss.dfp = fopen(vmem_filename, "r")) == NULL) {
error(INFO, LOGPRX"%s: %s\n", vmem_filename, strerror(errno));
result = FALSE;
goto exit;
}
fseek(vmss.dfp, 0L, SEEK_END);
if (vmss.memsize != ftell(vmss.dfp)) {
error(INFO, LOGPRX"%s: unexpected size\n", vmem_filename);
result = FALSE;
goto exit;
}
fseek(vmss.dfp, 0L, SEEK_SET);
fprintf(ofp, LOGPRX"vmem file: %s\n\n", vmem_filename);
exit:
if (fp)
fclose(fp);
if (vmem_filename)
free(vmem_filename);
if (result == FALSE) {
if (vmss.dfp)
fclose(vmss.dfp);
if (vmss.regs64) {
for (i = 0; i < vmss.num_vcpus; i++) {
if (vmss.regs64[i])
free(vmss.regs64[i]);
}
free(vmss.regs64);
}
if (vmss.vcpu_regs)
free(vmss.vcpu_regs);
}
return result;
}
int
vmware_guestdump_memory_dump(FILE *ofp)
{
fprintf(ofp, "vmware_guestdump:\n");
fprintf(ofp, " Header: version=%d num_vcpus=%llu\n",
GUESTDUMP_VERSION, (ulonglong)vmss.num_vcpus);
fprintf(ofp, "Total memory: %llu\n", (ulonglong)vmss.memsize);
if (vmss.regionscount > 1) {
uint64_t holes_sum = 0;
unsigned i;
fprintf(ofp, "Memory regions[%d]:\n", vmss.regionscount);
fprintf(ofp, " [0x%016x-", 0);
for (i = 0; i < vmss.regionscount - 1; i++) {
fprintf(ofp, "0x%016llx]\n", (ulonglong)vmss.regions[i].startpagenum << VMW_PAGE_SHIFT);
fprintf(ofp, " [0x%016llx-", (ulonglong)vmss.regions[i].startppn << VMW_PAGE_SHIFT);
holes_sum += vmss.regions[i].startppn - vmss.regions[i].startpagenum;
}
fprintf(ofp, "0x%016llx]\n", (ulonglong)vmss.memsize + (holes_sum << VMW_PAGE_SHIFT));
}
return TRUE;
}