KVM: arm64: Exclude host_debug_data from vcpu_arch

Keeping host_debug_state on a per-vcpu basis is completely
pointless. The lifetime of this data is only that of the inner
run-loop, which means it is never accessed outside of the core
EL2 code.

Move the structure into kvm_host_data, and save over 500 bytes
per vcpu.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

1 files changed, 17 insertions, 14 deletions

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index f41db42529df..d7bcb8ce1d7b 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -543,6 +543,19 @@ struct kvm_cpu_context {
  */
 struct kvm_host_data {
 	struct kvm_cpu_context host_ctxt;
+
+	/*
+	 * host_debug_state contains the host registers which are
+	 * saved and restored during world switches.
+	 */
+	 struct {
+		/* {Break,watch}point registers */
+		struct kvm_guest_debug_arch regs;
+		/* Statistical profiling extension */
+		u64 pmscr_el1;
+		/* Self-hosted trace */
+		u64 trfcr_el1;
+	} host_debug_state;
 };
 
 struct kvm_host_psci_config {
@@ -638,11 +651,10 @@ struct kvm_vcpu_arch {
 	 * We maintain more than a single set of debug registers to support
 	 * debugging the guest from the host and to maintain separate host and
 	 * guest state during world switches. vcpu_debug_state are the debug
-	 * registers of the vcpu as the guest sees them.  host_debug_state are
-	 * the host registers which are saved and restored during
-	 * world switches. external_debug_state contains the debug
-	 * values we want to debug the guest. This is set via the
-	 * KVM_SET_GUEST_DEBUG ioctl.
+	 * registers of the vcpu as the guest sees them.
+	 *
+	 * external_debug_state contains the debug values we want to debug the
+	 * guest. This is set via the KVM_SET_GUEST_DEBUG ioctl.
 	 *
 	 * debug_ptr points to the set of debug registers that should be loaded
 	 * onto the hardware when running the guest.
@@ -654,15 +666,6 @@ struct kvm_vcpu_arch {
 	struct user_fpsimd_state *host_fpsimd_state;	/* hyp VA */
 	struct task_struct *parent_task;
 
-	struct {
-		/* {Break,watch}point registers */
-		struct kvm_guest_debug_arch regs;
-		/* Statistical profiling extension */
-		u64 pmscr_el1;
-		/* Self-hosted trace */
-		u64 trfcr_el1;
-	} host_debug_state;
-
 	/* VGIC state */
 	struct vgic_cpu vgic_cpu;
 	struct arch_timer_cpu timer_cpu;