x86: Support vCPU CPUID keep same topology as pCPU

At present the Guest use the cpu id (enum number) as the APIC ID in vCPU
CPUID and set the different topology with pCPU.

To support the feature vCPU has the same topology as pCPU, vCPU need the
same APIC ID as pCPU. So let vCPU can use the APIC ID from pCPU in
vCPU's CPUID and keep pCPU's topology related information (include CPU
count and topology mask) unchanged.

Now this change is a preliminary preparation and doesn't work.
Additional feature options and corresponding CPU number and CPU affinity
settings are still required.

BUG=b:197875305
TEST=cargo build
TEST=./test_all

Change-Id: I04150ac6c35534d0ff56667b01f448da2ca9f9fc
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3217034
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Chirantan Ekbote <chirantan@chromium.org>
Reviewed-by: Chirantan Ekbote <chirantan@chromium.org>
Reviewed-by: David Stevens <stevensd@chromium.org>

x86_64/src/cpuid.rs

@@ -42,6 +42,7 @@ fn filter_cpuid(
     cpuid: &mut hypervisor::CpuId,
     irq_chip: &dyn IrqChipX86_64,
     no_smt: bool,
+    host_cpu_topology: bool,
 ) {
     let entries = &mut cpuid.cpu_id_entries;
 
@@ -60,6 +61,12 @@ fn filter_cpuid(
                 if irq_chip.check_capability(IrqChipCap::TscDeadlineTimer) {
                     entry.ecx |= 1 << ECX_TSC_DEADLINE_TIMER_SHIFT;
                 }
+
+                if host_cpu_topology {
+                    entry.ebx |= EBX_CLFLUSH_CACHELINE << EBX_CLFLUSH_SIZE_SHIFT;
+                    continue;
+                }
+
                 entry.ebx = (vcpu_id << EBX_CPUID_SHIFT) as u32
                     | (EBX_CLFLUSH_CACHELINE << EBX_CLFLUSH_SIZE_SHIFT);
                 if cpu_count > 1 {
@@ -82,6 +89,11 @@ fn filter_cpuid(
                     entry.ecx = result.ecx;
                     entry.edx = result.edx;
                 }
+
+                if host_cpu_topology {
+                    continue;
+                }
+
                 entry.eax &= !0xFC000000;
                 if cpu_count > 1 {
                     let cpu_cores = if no_smt {
@@ -99,6 +111,9 @@ fn filter_cpuid(
                 entry.ecx &= !(1 << ECX_EPB_SHIFT);
             }
             0xB | 0x1F => {
+                if host_cpu_topology {
+                    continue;
+                }
                 // Extended topology enumeration / V2 Extended topology enumeration
                 // NOTE: these will need to be split if any of the fields that differ between
                 // the two versions are to be set.
@@ -145,6 +160,9 @@ fn filter_cpuid(
 /// * `vcpu` - `VcpuX86_64` for setting CPU ID.
 /// * `vcpu_id` - The vcpu index of `vcpu`.
 /// * `nrcpus` - The number of vcpus being used by this VM.
+/// * `no_smt` - The flag indicates whether vCPUs supports SMT.
+/// * `host_cpu_topology` - The flag indicates whether vCPUs use mirror CPU topology. Now
+///                         `--host-cpu-topology` hasn't been supported, and just set it as false.
 pub fn setup_cpuid(
     hypervisor: &dyn HypervisorX86_64,
     irq_chip: &dyn IrqChipX86_64,
@@ -152,12 +170,20 @@ pub fn setup_cpuid(
     vcpu_id: usize,
     nrcpus: usize,
     no_smt: bool,
+    host_cpu_topology: bool,
 ) -> Result<()> {
     let mut cpuid = hypervisor
         .get_supported_cpuid()
         .map_err(Error::GetSupportedCpusFailed)?;
 
-    filter_cpuid(vcpu_id, nrcpus, &mut cpuid, irq_chip, no_smt);
+    filter_cpuid(
+        vcpu_id,
+        nrcpus,
+        &mut cpuid,
+        irq_chip,
+        no_smt,
+        host_cpu_topology,
+    );
 
     vcpu.set_cpuid(&cpuid)
         .map_err(Error::SetSupportedCpusFailed)
@@ -201,7 +227,7 @@ mod tests {
             edx: 0,
             ..Default::default()
         });
-        filter_cpuid(1, 2, &mut cpuid, &irq_chip, false);
+        filter_cpuid(1, 2, &mut cpuid, &irq_chip, false, false);
 
         let entries = &mut cpuid.cpu_id_entries;
         assert_eq!(entries[0].function, 0);

x86_64/src/lib.rs

@@ -574,7 +574,7 @@ impl arch::LinuxArch for X8664arch {
         has_bios: bool,
         no_smt: bool,
     ) -> Result<()> {
-        cpuid::setup_cpuid(hypervisor, irq_chip, vcpu, vcpu_id, num_cpus, no_smt)
+        cpuid::setup_cpuid(hypervisor, irq_chip, vcpu, vcpu_id, num_cpus, no_smt, false)
             .map_err(Error::SetupCpuid)?;
 
         if has_bios {

x86_64/src/test_integration.rs

@@ -236,7 +236,7 @@ where
                 .add_vcpu(0, &vcpu)
                 .expect("failed to add vcpu to irqchip");
 
-            setup_cpuid(&hyp, &irq_chip, &vcpu, 0, 1, false).unwrap();
+            setup_cpuid(&hyp, &irq_chip, &vcpu, 0, 1, false, false).unwrap();
             setup_msrs(&vcpu, END_ADDR_BEFORE_32BITS).unwrap();
 
             setup_regs(