[PATCH v2 08/15] arm64: KVM/debug: drop pmscr_el1 and use sys_regs[PMSCR_EL1] in kvm_cpu_context

Sudeep Holla
2019-05-23T10:35:50Z

kvm_cpu_context now has support to stash the complete SPE buffer control
context. We no longer need the pmscr_el1 kvm_vcpu_arch and it can be
dropped.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
arch/arm64/include/asm/kvm_host.h | 2 --
arch/arm64/kvm/hyp/debug-sr.c | 26 +++++++++++++++-----------
2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 559aa6931291..6921fdfd477b 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -310,8 +310,6 @@ struct kvm_vcpu_arch {
struct {
/* {Break,watch}point registers */
struct kvm_guest_debug_arch regs;
- /* Statistical profiling extension */
- u64 pmscr_el1;
} host_debug_state;

/* VGIC state */
diff --git a/arch/arm64/kvm/hyp/debug-sr.c b/arch/arm64/kvm/hyp/debug-sr.c
index 618884df1dc4..a2714a5eb3e9 100644
--- a/arch/arm64/kvm/hyp/debug-sr.c
+++ b/arch/arm64/kvm/hyp/debug-sr.c
@@ -66,19 +66,19 @@
default: write_debug(ptr[0], reg, 0); \
}

-static void __hyp_text __debug_save_spe_nvhe(u64 *pmscr_el1)
+static void __hyp_text __debug_save_spe_nvhe(struct kvm_cpu_context *ctxt)
{
u64 reg;

/* Clear pmscr in case of early return */
- *pmscr_el1 = 0;
+ ctxt->sys_regs[PMSCR_EL1] = 0;

/* SPE present on this CPU? */
if (!cpuid_feature_extract_unsigned_field(read_sysreg(id_aa64dfr0_el1),
ID_AA64DFR0_PMSVER_SHIFT))
return;

- /* Yes; is it owned by EL3? */
+ /* Yes; is it owned by higher EL? */
reg = read_sysreg_s(SYS_PMBIDR_EL1);
if (reg & BIT(SYS_PMBIDR_EL1_P_SHIFT))
return;
@@ -89,7 +89,7 @@ static void __hyp_text __debug_save_spe_nvhe(u64 *pmscr_el1)
return;

/* Yes; save the control register and disable data generation */
- *pmscr_el1 = read_sysreg_el1_s(SYS_PMSCR);
+ ctxt->sys_regs[PMSCR_EL1] = read_sysreg_el1_s(SYS_PMSCR);
write_sysreg_el1_s(0, SYS_PMSCR);
isb();

@@ -98,16 +98,16 @@ static void __hyp_text __debug_save_spe_nvhe(u64 *pmscr_el1)
dsb(nsh);
}

-static void __hyp_text __debug_restore_spe_nvhe(u64 pmscr_el1)
+static void __hyp_text __debug_restore_spe_nvhe(struct kvm_cpu_context *ctxt)
{
- if (!pmscr_el1)
+ if (!ctxt->sys_regs[PMSCR_EL1])
return;

/* The host page table is installed, but not yet synchronised */
isb();

/* Re-enable data generation */
- write_sysreg_el1_s(pmscr_el1, SYS_PMSCR);
+ write_sysreg_el1_s(ctxt->sys_regs[PMSCR_EL1], SYS_PMSCR);
}

static void __hyp_text __debug_save_state(struct kvm_vcpu *vcpu,
@@ -175,14 +175,15 @@ void __hyp_text __debug_restore_host_context(struct kvm_vcpu *vcpu)
struct kvm_guest_debug_arch *host_dbg;
struct kvm_guest_debug_arch *guest_dbg;

+ host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
+ guest_ctxt = &vcpu->arch.ctxt;
+
if (!has_vhe())
- __debug_restore_spe_nvhe(vcpu->arch.host_debug_state.pmscr_el1);
+ __debug_restore_spe_nvhe(host_ctxt);

if (!(vcpu->arch.flags & KVM_ARM64_DEBUG_DIRTY))
return;

- host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
- guest_ctxt = &vcpu->arch.ctxt;
host_dbg = &vcpu->arch.host_debug_state.regs;
guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);

@@ -198,8 +199,11 @@ void __hyp_text __debug_save_host_context(struct kvm_vcpu *vcpu)
* Non-VHE: Disable and flush SPE data generation
* VHE: The vcpu can run, but it can't hide.
*/
+ struct kvm_cpu_context *host_ctxt;
+
+ host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
if (!has_vhe())
- __debug_save_spe_nvhe(&vcpu->arch.host_debug_state.pmscr_el1);
+ __debug_save_spe_nvhe(host_ctxt);
}

void __hyp_text __debug_save_guest_context(struct kvm_vcpu *vcpu)