Add helpers to handle 64-bit APIC read/writes via MSRs to deduplicate the
x2APIC and Hyper-V code needed to service reads/writes to ICR. Future
support for IPI virtualization will add yet another path where KVM must
handle 64-bit APIC MSR reads/write (to ICR).
Opportunistically fix the comment in the write path; ICR2 holds the
destination (if there's no shorthand), not the vector.
No functional change intended.
Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
arch/x86/kvm/lapic.c | 59 ++++++++++++++++++++++----------------------
1 file changed, 29 insertions(+), 30 deletions(-)
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index deac73ce2de5..f72f3043134e 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -2782,6 +2782,30 @@ int kvm_lapic_set_vapic_addr(struct kvm_vcpu *vcpu, gpa_t vapic_addr)
return 0;
}
+static int kvm_lapic_msr_read(struct kvm_lapic *apic, u32 reg, u64 *data)
+{
+ u32 low, high = 0;
+
+ if (kvm_lapic_reg_read(apic, reg, 4, &low))
+ return 1;
+
+ if (reg == APIC_ICR &&
+ WARN_ON_ONCE(kvm_lapic_reg_read(apic, APIC_ICR2, 4, &high)))
+ return 1;
+
+ *data = (((u64)high) << 32) | low;
+
+ return 0;
+}
+
+static int kvm_lapic_msr_write(struct kvm_lapic *apic, u32 reg, u64 data)
+{
+ /* For 64-bit ICR writes, set ICR2 (dest) before ICR (command). */
+ if (reg == APIC_ICR)
+ kvm_lapic_reg_write(apic, APIC_ICR2, (u32)(data >> 32));
+ return kvm_lapic_reg_write(apic, reg, (u32)data);
+}
+
int kvm_x2apic_msr_write(struct kvm_vcpu *vcpu, u32 msr, u64 data)
{
struct kvm_lapic *apic = vcpu->arch.apic;
@@ -2793,16 +2817,13 @@ int kvm_x2apic_msr_write(struct kvm_vcpu *vcpu, u32 msr, u64 data)
if (reg == APIC_ICR2)
return 1;
- /* if this is ICR write vector before command */
- if (reg == APIC_ICR)
- kvm_lapic_reg_write(apic, APIC_ICR2, (u32)(data >> 32));
- return kvm_lapic_reg_write(apic, reg, (u32)data);
+ return kvm_lapic_msr_write(apic, reg, data);
}
int kvm_x2apic_msr_read(struct kvm_vcpu *vcpu, u32 msr, u64 *data)
{
struct kvm_lapic *apic = vcpu->arch.apic;
- u32 reg = (msr - APIC_BASE_MSR) << 4, low, high = 0;
+ u32 reg = (msr - APIC_BASE_MSR) << 4;
if (!lapic_in_kernel(vcpu) || !apic_x2apic_mode(apic))
return 1;
@@ -2810,45 +2831,23 @@ int kvm_x2apic_msr_read(struct kvm_vcpu *vcpu, u32 msr, u64 *data)
if (reg == APIC_DFR || reg == APIC_ICR2)
return 1;
- if (kvm_lapic_reg_read(apic, reg, 4, &low))
- return 1;
- if (reg == APIC_ICR)
- kvm_lapic_reg_read(apic, APIC_ICR2, 4, &high);
-
- *data = (((u64)high) << 32) | low;
-
- return 0;
+ return kvm_lapic_msr_read(apic, reg, data);
}
int kvm_hv_vapic_msr_write(struct kvm_vcpu *vcpu, u32 reg, u64 data)
{
- struct kvm_lapic *apic = vcpu->arch.apic;
-
if (!lapic_in_kernel(vcpu))
return 1;
- /* if this is ICR write vector before command */
- if (reg == APIC_ICR)
- kvm_lapic_reg_write(apic, APIC_ICR2, (u32)(data >> 32));
- return kvm_lapic_reg_write(apic, reg, (u32)data);
+ return kvm_lapic_msr_write(vcpu->arch.apic, reg, data);
}
int kvm_hv_vapic_msr_read(struct kvm_vcpu *vcpu, u32 reg, u64 *data)
{
- struct kvm_lapic *apic = vcpu->arch.apic;
- u32 low, high = 0;
-
if (!lapic_in_kernel(vcpu))
return 1;
- if (kvm_lapic_reg_read(apic, reg, 4, &low))
- return 1;
- if (reg == APIC_ICR)
- kvm_lapic_reg_read(apic, APIC_ICR2, 4, &high);
-
- *data = (((u64)high) << 32) | low;
-
- return 0;
+ return kvm_lapic_msr_read(vcpu->arch.apic, reg, data);
}
int kvm_lapic_set_pv_eoi(struct kvm_vcpu *vcpu, u64 data, unsigned long len)
--
2.35.0.263.gb82422642f-goog
