[13/15] arm64: kvm: Add comments around __hyp_text_ symbol aliases

Commit Message

David Brazdil April 30, 2020, 2:48 p.m. UTC

This patch is part of a series which builds KVM's non-VHE hyp code separately
from VHE and the rest of the kernel.

With all source files split between VHE/nVHE, add comments around the list of
symbols where nVHE code still links against kernel proper. Split them into
groups and explain how each group is currently used.

Some of these dependencies will be removed in the future.

Signed-off-by: David Brazdil <[e-mail]>
---
 arch/arm64/kernel/image-vars.h | 49 +++++++++++++++++++++-------------
 1 file changed, 31 insertions(+), 18 deletions(-)

Patch

diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
index e272eedfe19a..04a3ee21e694 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/arch/arm64/kernel/image-vars.h
@@ -61,24 +61,37 @@  __efistub__ctype		= _ctype;
  * memory mappings.
  */
 
-__hyp_text___icache_flags = __icache_flags;
-__hyp_text___kvm_handle_stub_hvc = __kvm_handle_stub_hvc;
-__hyp_text_arm64_const_caps_ready = arm64_const_caps_ready;
-__hyp_text_arm64_enable_wa2_handling = arm64_enable_wa2_handling;
-__hyp_text_arm64_ssbd_callback_required = arm64_ssbd_callback_required;
-__hyp_text_cpu_hwcap_keys = cpu_hwcap_keys;
-__hyp_text_cpu_hwcaps = cpu_hwcaps;
-__hyp_text_kimage_voffset = kimage_voffset;
-__hyp_text_kvm_host_data = kvm_host_data;
-__hyp_text_kvm_patch_vector_branch = kvm_patch_vector_branch;
-__hyp_text_kvm_update_va_mask = kvm_update_va_mask;
-__hyp_text_kvm_vgic_global_state = kvm_vgic_global_state;
-__hyp_text_panic = panic;
-__hyp_text_physvirt_offset = physvirt_offset;
-__hyp_text_sve_load_state = sve_load_state;
-__hyp_text_sve_save_state = sve_save_state;
-__hyp_text_vgic_v2_cpuif_trap = vgic_v2_cpuif_trap;
-__hyp_text_vgic_v3_cpuif_trap = vgic_v3_cpuif_trap;
+/* If nVHE code panics, it ERETs into panic() in EL1. */
+__hyp_text_panic			= panic;
+
+/* Stub HVC IDs are routed to a handler in .hyp.idmap.text. Executed in EL2. */
+__hyp_text___kvm_handle_stub_hvc	= __kvm_handle_stub_hvc;
+
+/* Alternative callbacks, referenced in .altinstructions. Executed in EL1. */
+__hyp_text_arm64_enable_wa2_handling	= arm64_enable_wa2_handling;
+__hyp_text_kvm_patch_vector_branch	= kvm_patch_vector_branch;
+__hyp_text_kvm_update_va_mask		= kvm_update_va_mask;
+
+/* Values used to convert between memory mappings, read-only after init. */
+__hyp_text_kimage_voffset		= kimage_voffset;
+__hyp_text_physvirt_offset		= physvirt_offset;
+
+/* Data shared with the kernel. */
+__hyp_text_cpu_hwcaps			= cpu_hwcaps;
+__hyp_text_cpu_hwcap_keys		= cpu_hwcap_keys;
+__hyp_text___icache_flags		= __icache_flags;
+__hyp_text_kvm_vgic_global_state	= kvm_vgic_global_state;
+__hyp_text_arm64_ssbd_callback_required	= arm64_ssbd_callback_required;
+__hyp_text_kvm_host_data		= kvm_host_data;
+
+/* Static keys shared with the kernel. */
+__hyp_text_arm64_const_caps_ready	= arm64_const_caps_ready;
+__hyp_text_vgic_v2_cpuif_trap		= vgic_v2_cpuif_trap;
+__hyp_text_vgic_v3_cpuif_trap		= vgic_v3_cpuif_trap;
+
+/* SVE support, currently unused by nVHE. */
+__hyp_text_sve_save_state		= sve_save_state;
+__hyp_text_sve_load_state		= sve_load_state;
 
 #endif /* CONFIG_KVM */