Track the baseline guest value for mdcr_el2 in struct kvm_vcpu_arch.
Use this value when setting mdcr_el2 for the guest.
Currently this value is unchanged, but the following patches will set
trapping bits based on features supported for the guest.
No functional change intended.
Signed-off-by: Reiji Watanabe <reijiw@xxxxxxxxxx>
---
arch/arm64/include/asm/kvm_arm.h | 16 ++++++++++++++++
arch/arm64/kvm/arm.c | 1 +
arch/arm64/kvm/debug.c | 13 ++++---------
3 files changed, 21 insertions(+), 9 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 3f74fb16104e..90be933b5f08 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -333,6 +333,22 @@
BIT(18) | \
GENMASK(16, 15))
+/*
+ * The default value for the guest below also clears MDCR_EL2_E2PB_MASK
+ * and MDCR_EL2_E2TB_MASK to disable guest access to the profiling and
+ * trace buffers.
+ */
+#define MDCR_GUEST_FLAGS_DEFAULT \
+ (MDCR_EL2_TPM | MDCR_EL2_TPMS | MDCR_EL2_TTRF | \
+ MDCR_EL2_TPMCR | MDCR_EL2_TDRA | MDCR_EL2_TDOSA)
+
+/* Bits that are copied from vcpu->arch.mdcr_el2 to set mdcr_el2 for guest. */
+#define MDCR_GUEST_FLAGS_TRACKED_MASK \
+ (MDCR_EL2_TPM | MDCR_EL2_TPMS | MDCR_EL2_TTRF | \
+ MDCR_EL2_TPMCR | MDCR_EL2_TDRA | MDCR_EL2_TDOSA | \
+ (MDCR_EL2_E2PB_MASK << MDCR_EL2_E2PB_SHIFT))
+
+
/* For compatibility with fault code shared with 32-bit */
#define FSC_FAULT ESR_ELx_FSC_FAULT
#define FSC_ACCESS ESR_ELx_FSC_ACCESS
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index e80c059b41d5..69189907579c 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1123,6 +1123,7 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu,
}
vcpu_reset_hcr(vcpu);
+ vcpu->arch.mdcr_el2 = MDCR_GUEST_FLAGS_DEFAULT;
if (has_vhe())
vcpu->arch.cptr_el2 = CPTR_EL2_VHE_GUEST_DEFAULT;
else
diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c
index 6eb146d908f8..8e1243972804 100644
--- a/arch/arm64/kvm/debug.c
+++ b/arch/arm64/kvm/debug.c
@@ -84,16 +84,11 @@ void kvm_arm_init_debug(void)
static void kvm_arm_setup_mdcr_el2(struct kvm_vcpu *vcpu)
{
/*
- * This also clears MDCR_EL2_E2PB_MASK and MDCR_EL2_E2TB_MASK
- * to disable guest access to the profiling and trace buffers
+ * Keep the vcpu->arch.mdcr_el2 bits that are specified by
+ * MDCR_GUEST_FLAGS_TRACKED_MASK.
*/
- vcpu->arch.mdcr_el2 = __this_cpu_read(mdcr_el2) & MDCR_EL2_HPMN_MASK;
- vcpu->arch.mdcr_el2 |= (MDCR_EL2_TPM |
- MDCR_EL2_TPMS |
- MDCR_EL2_TTRF |
- MDCR_EL2_TPMCR |
- MDCR_EL2_TDRA |
- MDCR_EL2_TDOSA);
+ vcpu->arch.mdcr_el2 &= MDCR_GUEST_FLAGS_TRACKED_MASK;
+ vcpu->arch.mdcr_el2 |= __this_cpu_read(mdcr_el2) & MDCR_EL2_HPMN_MASK;
/* Is the VM being debugged by userspace? */
if (vcpu->guest_debug)
--
2.36.0.rc0.470.gd361397f0d-goog
