[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[PATCH v2 04/16] hw/i386/vmport: Set EAX to -1 on failed and unsupported
From: |
Liran Alon |
Subject: |
[PATCH v2 04/16] hw/i386/vmport: Set EAX to -1 on failed and unsupported commands |
Date: |
Tue, 10 Mar 2020 18:53:20 +0200 |
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 <address@hidden>
Signed-off-by: Liran Alon <address@hidden>
---
hw/i386/vmport.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/hw/i386/vmport.c b/hw/i386/vmport.c
index 736d78263889..8115852720c8 100644
--- a/hw/i386/vmport.c
+++ b/hw/i386/vmport.c
@@ -75,17 +75,23 @@ 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->version > 1) {
+ eax = UINT32_MAX;
+ }
out:
/*
--
2.20.1
- [PATCH v2 00/16]: hw/i386/vmport: Bug fixes and improvements, Liran Alon, 2020/03/10
- [PATCH v2 01/16] hw/i386/vmport: Add device properties, Liran Alon, 2020/03/10
- [PATCH v2 02/16] hw/i386/vmport: Add compatability version field, Liran Alon, 2020/03/10
- [PATCH v2 04/16] hw/i386/vmport: Set EAX to -1 on failed and unsupported commands,
Liran Alon <=
- [PATCH v2 03/16] hw/i386/vmport: Propagate IOPort read to vCPU EAX register, Liran Alon, 2020/03/10
- [PATCH v2 05/16] hw/i386/vmport: Introduce vmx-version property, Liran Alon, 2020/03/10
- [PATCH v2 06/16] hw/i386/vmport: Report VMX type in CMD_GETVERSION, Liran Alon, 2020/03/10
- [PATCH v2 07/16] hw/i386/vmport: Introduce vmport.h, Liran Alon, 2020/03/10
- [PATCH v2 09/16] hw/i386/vmport: Add support for CMD_GETBIOSUUID, Liran Alon, 2020/03/10
- [PATCH v2 10/16] hw/i386/vmport: Add support for CMD_GETTIME, Liran Alon, 2020/03/10
- [PATCH v2 11/16] hw/i386/vmport: Add support for CMD_GETTIMEFULL, Liran Alon, 2020/03/10
- [PATCH v2 12/16] hw/i386/vmport: Add support for CMD_GET_VCPU_INFO, Liran Alon, 2020/03/10
- [PATCH v2 13/16] hw/i386/vmport: Allow x2apic without IR, Liran Alon, 2020/03/10
- [PATCH v2 14/16] i386/cpu: Store LAPIC bus frequency in CPU structure, Liran Alon, 2020/03/10