This command returns to guest information on LAPIC bus frequency and TSC
frequency.
One can see how this interface is used by Linux vmware_platform_setup()
introduced in Linux commit 88b094fb8d4f ("x86: Hypervisor detection and
get tsc_freq from hypervisor").
Reviewed-by: Nikita Leshenko <nikita.leshche...@oracle.com>
Signed-off-by: Liran Alon <liran.a...@oracle.com>
---
hw/i386/vmport.c | 19 +++++++++++++++++++
include/hw/i386/vmport.h | 1 +
2 files changed, 20 insertions(+)
diff --git a/hw/i386/vmport.c b/hw/i386/vmport.c
index 1664a6b97332..9d3921cf418d 100644
--- a/hw/i386/vmport.c
+++ b/hw/i386/vmport.c
@@ -176,6 +176,24 @@ static uint32_t vmport_cmd_ram_size(void *opaque, uint32_t
addr)
return ram_size;
}
+static uint32_t vmport_cmd_get_hz(void *opaque, uint32_t addr)
+{
+ X86CPU *cpu = X86_CPU(current_cpu);
+
+ if (cpu->env.tsc_khz && cpu->env.apic_bus_freq) {
+ uint64_t tsc_freq = (uint64_t)cpu->env.tsc_khz * 1000;
+
+ cpu->env.regs[R_ECX] = cpu->env.apic_bus_freq;
+ cpu->env.regs[R_EBX] = (uint32_t)(tsc_freq >> 32);
+ cpu->env.regs[R_EAX] = (uint32_t)tsc_freq;
+ } else {
+ /* Signal cmd as not supported */
+ cpu->env.regs[R_EBX] = UINT32_MAX;
+ }
+
+ return cpu->env.regs[R_EAX];
+}
+
static uint32_t vmport_cmd_time(void *opaque, uint32_t addr)
{
X86CPU *cpu = X86_CPU(current_cpu);
@@ -265,6 +283,7 @@ static void vmport_realizefn(DeviceState *dev, Error **errp)
if (s->compat_flags & VMPORT_COMPAT_CMDS_V2) {
vmport_register(VMPORT_CMD_GETBIOSUUID, vmport_cmd_get_bios_uuid,
NULL);
vmport_register(VMPORT_CMD_GETTIME, vmport_cmd_time, NULL);
+ vmport_register(VMPORT_CMD_GETHZ, vmport_cmd_get_hz, NULL);
vmport_register(VMPORT_CMD_GETTIMEFULL, vmport_cmd_time_full, NULL);
vmport_register(VMPORT_CMD_GET_VCPU_INFO, vmport_cmd_get_vcpu_info,
NULL);
diff --git a/include/hw/i386/vmport.h b/include/hw/i386/vmport.h
index 34cc050b1ffa..aee809521aa0 100644
--- a/include/hw/i386/vmport.h
+++ b/include/hw/i386/vmport.h
@@ -12,6 +12,7 @@ typedef enum {
VMPORT_CMD_VMMOUSE_DATA = 39,
VMPORT_CMD_VMMOUSE_STATUS = 40,
VMPORT_CMD_VMMOUSE_COMMAND = 41,
+ VMPORT_CMD_GETHZ = 45,
VMPORT_CMD_GETTIMEFULL = 46,
VMPORT_CMD_GET_VCPU_INFO = 68,
VMPORT_ENTRIES
--
2.20.1
