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| author | Liran Alon <liran.alon@oracle.com> | 2020-03-12 18:54:19 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2020-06-10 12:09:44 -0400 |
| commit | 0342ee761ef27a0def476dab3e284f924b3c801e (patch) | |
| tree | 3c72df6987377ef170bf9e28c764162188e710d3 /hw | |
| parent | b889212973dabee119a1ab21326a27fc51b88d6d (diff) | |
| download | qemu-0342ee761ef27a0def476dab3e284f924b3c801e.zip qemu-0342ee761ef27a0def476dab3e284f924b3c801e.tar.gz qemu-0342ee761ef27a0def476dab3e284f924b3c801e.tar.bz2 | |
hw/i386/vmport: Set EAX to -1 on failed and unsupported commands
This is used as a signal for VMware Tools to know if a command it
attempted to invoke, failed or is unsupported. As a result, VMware Tools
will either report failure to user or fallback to another backdoor command
in attempt to perform some operation.
A few examples:
* open-vm-tools TimeSyncReadHost() function fallbacks to
CMD_GETTIMEFULL command when CMD_GETTIMEFULL_WITH_LAG
fails/unsupported.
* open-vm-tools Hostinfo_NestingSupported() function verifies
EAX != -1 to check for success.
* open-vm-tools Hostinfo_VCPUInfoBackdoor() functions checks
if reserved-bit is set to indicate command is unimplemented.
Reviewed-by: Nikita Leshenko <nikita.leshchenko@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Message-Id: <20200312165431.82118-5-liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'hw')
| -rw-r--r-- | hw/core/machine.c | 1 | ||||
| -rw-r--r-- | hw/i386/vmport.c | 19 |
2 files changed, 16 insertions, 4 deletions
diff --git a/hw/core/machine.c b/hw/core/machine.c index 83f0fe5..fc209d7 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -44,6 +44,7 @@ GlobalProperty hw_compat_4_2[] = { { "qxl-vga", "revision", "4" }, { "fw_cfg", "acpi-mr-restore", "false" }, { "vmport", "x-read-set-eax", "off" }, + { "vmport", "x-signal-unsupported-cmd", "off" }, }; const size_t hw_compat_4_2_len = G_N_ELEMENTS(hw_compat_4_2); diff --git a/hw/i386/vmport.c b/hw/i386/vmport.c index 3bb420a..730b61f 100644 --- a/hw/i386/vmport.c +++ b/hw/i386/vmport.c @@ -44,9 +44,12 @@ #define VMPORT_MAGIC 0x564D5868 /* Compatibility flags for migration */ -#define VMPORT_COMPAT_READ_SET_EAX_BIT 0 -#define VMPORT_COMPAT_READ_SET_EAX \ +#define VMPORT_COMPAT_READ_SET_EAX_BIT 0 +#define VMPORT_COMPAT_SIGNAL_UNSUPPORTED_CMD_BIT 1 +#define VMPORT_COMPAT_READ_SET_EAX \ (1 << VMPORT_COMPAT_READ_SET_EAX_BIT) +#define VMPORT_COMPAT_SIGNAL_UNSUPPORTED_CMD \ + (1 << VMPORT_COMPAT_SIGNAL_UNSUPPORTED_CMD_BIT) #define VMPORT(obj) OBJECT_CHECK(VMPortState, (obj), TYPE_VMPORT) @@ -87,17 +90,23 @@ static uint64_t vmport_ioport_read(void *opaque, hwaddr addr, eax = env->regs[R_EAX]; if (eax != VMPORT_MAGIC) { - goto out; + goto err; } command = env->regs[R_ECX]; trace_vmport_command(command); if (command >= VMPORT_ENTRIES || !s->func[command]) { qemu_log_mask(LOG_UNIMP, "vmport: unknown command %x\n", command); - goto out; + goto err; } eax = s->func[command](s->opaque[command], addr); + goto out; + +err: + if (s->compat_flags & VMPORT_COMPAT_SIGNAL_UNSUPPORTED_CMD) { + eax = UINT32_MAX; + } out: /* @@ -168,6 +177,8 @@ static Property vmport_properties[] = { /* Used to enforce compatibility for migration */ DEFINE_PROP_BIT("x-read-set-eax", VMPortState, compat_flags, VMPORT_COMPAT_READ_SET_EAX_BIT, true), + DEFINE_PROP_BIT("x-signal-unsupported-cmd", VMPortState, compat_flags, + VMPORT_COMPAT_SIGNAL_UNSUPPORTED_CMD_BIT, true), DEFINE_PROP_END_OF_LIST(), }; |