From 4679ac418314660a6b203cb54c4cd0b0844d7506 Mon Sep 17 00:00:00 2001
From: Noah Gold <nkgold@google.com>
Date: Thu, 9 Jun 2022 21:15:07 -0700
Subject: [PATCH] devices: add IrqChipX86_64::lapic_frequency.

This function is used to generate cpuid leaf 15H in some situations.

BUG=213152505
TEST=builds

Change-Id: Ia5a7c46b32f1bdba366a500caa650edb2e3ae99f
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3696534
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Commit-Queue: Noah Gold <nkgold@google.com>
---
 devices/src/irqchip/kvm/x86_64.rs | 12 ++++++++++++
 devices/src/irqchip/x86_64.rs     |  3 +++
 2 files changed, 15 insertions(+)

diff --git a/devices/src/irqchip/kvm/x86_64.rs b/devices/src/irqchip/kvm/x86_64.rs
index e9bd145817..0de348ef96 100644
--- a/devices/src/irqchip/kvm/x86_64.rs
+++ b/devices/src/irqchip/kvm/x86_64.rs
@@ -130,6 +130,12 @@ impl IrqChipX86_64 for KvmKernelIrqChip {
         }
     }
 
+    /// Get the lapic frequency in Hz
+    fn lapic_frequency(&self) -> u32 {
+        // KVM emulates the lapic to have a bus frequency of 1GHz
+        1_000_000_000
+    }
+
     /// Retrieves the state of the PIT. Gets the pit state via the KVM API.
     fn get_pit(&self) -> Result<PitState> {
         Ok(PitState::from(&self.vm.get_pit_state()?))
@@ -746,6 +752,12 @@ impl IrqChipX86_64 for KvmSplitIrqChip {
         }
     }
 
+    /// Get the lapic frequency in Hz
+    fn lapic_frequency(&self) -> u32 {
+        // KVM emulates the lapic to have a bus frequency of 1GHz
+        1_000_000_000
+    }
+
     /// Retrieves the state of the PIT. Gets the pit state via the KVM API.
     fn get_pit(&self) -> Result<PitState> {
         Ok(self.pit.lock().get_pit_state())
diff --git a/devices/src/irqchip/x86_64.rs b/devices/src/irqchip/x86_64.rs
index 5f2f599db0..3015d88495 100644
--- a/devices/src/irqchip/x86_64.rs
+++ b/devices/src/irqchip/x86_64.rs
@@ -35,6 +35,9 @@ pub trait IrqChipX86_64: IrqChip {
     /// Set the current state of the specified VCPU's local APIC
     fn set_lapic_state(&mut self, vcpu_id: usize, state: &LapicState) -> Result<()>;
 
+    /// Get the lapic frequency in Hz
+    fn lapic_frequency(&self) -> u32;
+
     /// Retrieves the state of the PIT.
     fn get_pit(&self) -> Result<PitState>;