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x86_64/cpuid.rs: Add cpu topology when no_smt isn't set

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When no_smt isn't set, guest works with hyperthread enabled, but crosvm
doesn't emulate processor topology cpuid at this case, so the output of
guest /proc/cpuinfo and lscpu is inconsitent, and guest cpuid is wrong.

This commit adds such support. If vcpu_num is >1 and is even, threads
per core is 2 and cores_num is vcpu_num/2. If vcpu_num is >1 and is odd,
threads per core is vcpu_num and cores_num is 1.

BUG=None
TEST=Check guest /proc/cpuinfo, lscpu, cpuid at different vcpu number

Change-Id: I8d9aaeac3fc911ee91bf2eb0586e457aac27a185
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2548450
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Dylan Reid <dgreid@chromium.org>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
This commit is contained in:
Xiong Zhang 2020-11-19 11:02:22 +08:00 committed by Commit Bot
parent b1394f719d
commit 0a086e6cbe
1 changed files with 33 additions and 12 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

45
x86_64/src/cpuid.rs
View file

@ -42,6 +42,7 @@ const EDX_HTT_SHIFT: u32 = 28; // Hyper Threading Enabled.
const ECX_TOPO_TYPE_SHIFT: u32 = 8; // Topology Level type.
const ECX_TOPO_SMT_TYPE: u32 = 1; // SMT type.
const ECX_TOPO_CORE_TYPE: u32 = 2; // CORE type.
const EAX_CPU_CORES_SHIFT: u32 = 26; // Index of cpu cores in the same physical package.
fn filter_cpuid(
vcpu_id: usize,
@ -90,6 +91,16 @@ fn filter_cpuid(
entry.edx = result.edx;
}
entry.eax &= !0xFC000000;
if cpu_count > 1 {
let cpu_cores = if no_smt {
cpu_count as u32
} else if cpu_count % 2 == 0 {
(cpu_count >> 1) as u32
} else {
1
};
entry.eax |= (cpu_cores - 1) << EAX_CPU_CORES_SHIFT;
}
}
6 => {
// Clear X86 EPB feature. No frequency selection in the hypervisor.
@ -100,22 +111,32 @@ fn filter_cpuid(
// NOTE: these will need to be split if any of the fields that differ between
// the two versions are to be set.
entry.edx = vcpu_id as u32; // x2APIC ID
if no_smt {
// Make it so that all VCPUs appear as different,
// non-hyperthreaded cores on the same package.
if entry.index == 0 {
if entry.index == 0 {
if no_smt || (cpu_count == 1) {
// Make it so that all VCPUs appear as different,
// non-hyperthreaded cores on the same package.
entry.eax = 0; // Shift to get id of next level
entry.ebx = 1; // Number of logical cpus at this level
entry.ecx = (ECX_TOPO_SMT_TYPE << ECX_TOPO_TYPE_SHIFT) | entry.index;
} else if entry.index == 1 {
entry.eax = 4;
entry.ebx = (cpu_count as u32) & 0xffff;
entry.ecx = (ECX_TOPO_CORE_TYPE << ECX_TOPO_TYPE_SHIFT) | entry.index;
} else if cpu_count % 2 == 0 {
// Each core has 2 hyperthreads
entry.eax = 1; // Shift to get id of next level
entry.ebx = 2; // Number of logical cpus at this level
} else {
entry.eax = 0;
entry.ebx = 0;
entry.ecx = 0;
// One core contain all the cpu_count hyperthreads
let cpu_bits: u32 = 32 - ((cpu_count - 1) as u32).leading_zeros();
entry.eax = cpu_bits; // Shift to get id of next level
entry.ebx = cpu_count as u32; // Number of logical cpus at this level
}
entry.ecx = (ECX_TOPO_SMT_TYPE << ECX_TOPO_TYPE_SHIFT) | entry.index;
} else if entry.index == 1 {
let cpu_bits: u32 = 32 - ((cpu_count - 1) as u32).leading_zeros();
entry.eax = cpu_bits;
entry.ebx = (cpu_count as u32) & 0xffff; // Number of logical cpus at this level
entry.ecx = (ECX_TOPO_CORE_TYPE << ECX_TOPO_TYPE_SHIFT) | entry.index;
} else {
entry.eax = 0;
entry.ebx = 0;
entry.ecx = 0;
}
}
_ => (),