KVM: arm: introduce kvm_arm_init/setup/clear_debug

This is a precursor for later patches which will need to do more to
setup debug state before entering the hyp.S switch code. The existing
functionality for setting mdcr_el2 has been moved out of hyp.S and now
uses the value kept in vcpu->arch.mdcr_el2.

As the assembler used to previously mask and preserve MDCR_EL2.HPMN I've
had to add a mechanism to save the value of mdcr_el2 as a per-cpu
variable during the initialisation code. The kernel never sets this
number so we are assuming the bootcode has set up the correct value
here.

This also moves the conditional setting of the TDA bit from the hyp code
into the C code which is currently used for the lazy debug register
context switch code.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index e896d2c196e63b79365e6f637c7b697c56c48f71..2b0bc8c5755288eae965cbad806f2b740c9526e2 100644 (file)
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -231,4 +231,8 @@ static inline void kvm_arch_sync_events(struct kvm *kvm) {}
 static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
 
+static inline void kvm_arm_init_debug(void) {}
+static inline void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) {}
+static inline void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) {}
+
 #endif /* __ARM_KVM_HOST_H__ */

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 1b693cb2d5b277452e36344fc23af5a07a85a7ca..77151b111d32d3f6c00b6d7fd2e4516a0fb59211 100644 (file)
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -543,6 +543,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
                        continue;
                }
 
+               kvm_arm_setup_debug(vcpu);
+
                /**************************************************************
                 * Enter the guest
                 */
@@ -557,6 +559,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
                 * Back from guest
                 *************************************************************/
 
+               kvm_arm_clear_debug(vcpu);
+
                /*
                 * We may have taken a host interrupt in HYP mode (ie
                 * while executing the guest). This interrupt is still
@@ -914,6 +918,8 @@ static void cpu_init_hyp_mode(void *dummy)
        vector_ptr = (unsigned long)__kvm_hyp_vector;
 
        __cpu_init_hyp_mode(boot_pgd_ptr, pgd_ptr, hyp_stack_ptr, vector_ptr);
+
+       kvm_arm_init_debug();
 }
 
 static int hyp_init_cpu_notify(struct notifier_block *self,

diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index 3c5fe685a2d69a55daf68fe40fa782a0843bb2f5..f5e40dae291ab2c20a6af7a98b154bc74af627f5 100644 (file)
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -132,6 +132,8 @@ extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
 
 extern u64 __vgic_v3_get_ich_vtr_el2(void);
 
+extern u32 __kvm_get_mdcr_el2(void);
+
 #endif
 
 #endif /* __ARM_KVM_ASM_H__ */

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 2709db2a7eac78a49fc75c072810b9ac41cc9e0a..c90c6a41c448c0410b1f5e0d4efff32dfdb1e103 100644 (file)
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -103,6 +103,7 @@ struct kvm_vcpu_arch {
 
        /* HYP configuration */
        u64 hcr_el2;
+       u32 mdcr_el2;
 
        /* Exception Information */
        struct kvm_vcpu_fault_info fault;
@@ -227,4 +228,8 @@ static inline void kvm_arch_sync_events(struct kvm *kvm) {}
 static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}
 static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
 
+void kvm_arm_init_debug(void);
+void kvm_arm_setup_debug(struct kvm_vcpu *vcpu);
+void kvm_arm_clear_debug(struct kvm_vcpu *vcpu);
+
 #endif /* __ARM64_KVM_HOST_H__ */

diff --cc arch/arm64/kernel/asm-offsets.c
Simple merge

diff --cc arch/arm64/kvm/Makefile
Simple merge

diff --cc arch/arm64/kvm/debug.c
Simple merge

diff --cc arch/arm64/kvm/hyp.S
Simple merge