diff mbox series

[v5,13/69] KVM: arm64: nv: Reset VMPIDR_EL2 and VPIDR_EL2 to sane values

Message ID 20211129200150.351436-14-maz@kernel.org (mailing list archive)
State New, archived
Headers show
Series KVM: arm64: ARMv8.3/8.4 Nested Virtualization support | expand

Commit Message

Marc Zyngier Nov. 29, 2021, 8 p.m. UTC 
From: Christoffer Dall <christoffer.dall@arm.com>

The VMPIDR_EL2 and VPIDR_EL2 are architecturally UNKNOWN at reset, but
let's be nice to a guest hypervisor behaving foolishly and reset these
to something reasonable anyway.

Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/sys_regs.c | 25 +++++++++++++++++++++----
 1 file changed, 21 insertions(+), 4 deletions(-)

Comments

Russell King (Oracle) Jan. 18, 2022, 3:52 p.m. UTC | #1 
On Mon, Nov 29, 2021 at 08:00:54PM +0000, Marc Zyngier wrote:
> From: Christoffer Dall <christoffer.dall@arm.com>
> 
> The VMPIDR_EL2 and VPIDR_EL2 are architecturally UNKNOWN at reset, but
> let's be nice to a guest hypervisor behaving foolishly and reset these
> to something reasonable anyway.
> 
> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
> Signed-off-by: Marc Zyngier <maz@kernel.org>

Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
diff mbox series

Patch

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index a23701f29858..730a24468915 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -618,7 +618,7 @@  static void reset_actlr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
 	vcpu_write_sys_reg(vcpu, actlr, ACTLR_EL1);
 }
 
-static void reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
+static u64 compute_reset_mpidr(struct kvm_vcpu *vcpu)
 {
 	u64 mpidr;
 
@@ -632,7 +632,24 @@  static void reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
 	mpidr = (vcpu->vcpu_id & 0x0f) << MPIDR_LEVEL_SHIFT(0);
 	mpidr |= ((vcpu->vcpu_id >> 4) & 0xff) << MPIDR_LEVEL_SHIFT(1);
 	mpidr |= ((vcpu->vcpu_id >> 12) & 0xff) << MPIDR_LEVEL_SHIFT(2);
-	vcpu_write_sys_reg(vcpu, (1ULL << 31) | mpidr, MPIDR_EL1);
+	mpidr |= (1ULL << 31);
+
+	return mpidr;
+}
+
+static void reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
+{
+	vcpu_write_sys_reg(vcpu, compute_reset_mpidr(vcpu), MPIDR_EL1);
+}
+
+static void reset_vmpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
+{
+	vcpu_write_sys_reg(vcpu, compute_reset_mpidr(vcpu), VMPIDR_EL2);
+}
+
+static void reset_vpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
+{
+	vcpu_write_sys_reg(vcpu, read_cpuid_id(), VPIDR_EL2);
 }
 
 static unsigned int pmu_visibility(const struct kvm_vcpu *vcpu,
@@ -1882,8 +1899,8 @@  static const struct sys_reg_desc sys_reg_descs[] = {
 	{ PMU_SYS_REG(SYS_PMCCFILTR_EL0), .access = access_pmu_evtyper,
 	  .reset = reset_val, .reg = PMCCFILTR_EL0, .val = 0 },
 
-	{ SYS_DESC(SYS_VPIDR_EL2), access_rw, reset_val, VPIDR_EL2, 0 },
-	{ SYS_DESC(SYS_VMPIDR_EL2), access_rw, reset_val, VMPIDR_EL2, 0 },
+	{ SYS_DESC(SYS_VPIDR_EL2), access_rw, reset_vpidr, VPIDR_EL2 },
+	{ SYS_DESC(SYS_VMPIDR_EL2), access_rw, reset_vmpidr, VMPIDR_EL2 },
 
 	{ SYS_DESC(SYS_SCTLR_EL2), access_sctlr_el2, reset_val, SCTLR_EL2, SCTLR_EL2_RES1 },
 	{ SYS_DESC(SYS_ACTLR_EL2), access_rw, reset_val, ACTLR_EL2, 0 },