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From:   David Brazdil <dbrazdil@google.com>
To:     Marc Zyngier <maz@kernel.org>, Will Deacon <will@kernel.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
        James Morse <james.morse@arm.com>,
        Julien Thierry <julien.thierry.kdev@gmail.com>,
        Suzuki K Poulose <suzuki.poulose@arm.com>
Cc:     kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org, android-kvm@google.com,
        kernel-team@android.com, David Brazdil <dbrazdil@google.com>
Subject: [PATCH v3 13/15] arm64: kvm: Add comments around __kvm_nvhe_ symbol aliases
Date:   Thu, 18 Jun 2020 13:25:35 +0100
Message-Id: <20200618122537.9625-14-dbrazdil@google.com>
In-Reply-To: <20200618122537.9625-1-dbrazdil@google.com>
References: <20200618122537.9625-1-dbrazdil@google.com>
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Sender: linux-kernel-owner@vger.kernel.org
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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 <dbrazdil@google.com>
---
 arch/arm64/kernel/image-vars.h | 53 +++++++++++++++++++++-------------
 1 file changed, 33 insertions(+), 20 deletions(-)

diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
index 2cc3e7673dc2..da8f39fae5e8 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/arch/arm64/kernel/image-vars.h
@@ -61,30 +61,43 @@ __efistub__ctype		= _ctype;
  * memory mappings.
  */
 
-__kvm_nvhe___hyp_panic_string = __hyp_panic_string;
-__kvm_nvhe___hyp_stub_vectors = __hyp_stub_vectors;
-__kvm_nvhe___icache_flags = __icache_flags;
-__kvm_nvhe_arm64_const_caps_ready = arm64_const_caps_ready;
-__kvm_nvhe_arm64_enable_wa2_handling = arm64_enable_wa2_handling;
-__kvm_nvhe_arm64_ssbd_callback_required = arm64_ssbd_callback_required;
-__kvm_nvhe_cpu_hwcap_keys = cpu_hwcap_keys;
-__kvm_nvhe_cpu_hwcaps = cpu_hwcaps;
+/* If nVHE code panics, it ERETs into panic() in EL1. */
+__kvm_nvhe___hyp_panic_string		= __hyp_panic_string;
+__kvm_nvhe_panic			= panic;
+
+/* Values used by the hyp-init vector. */
+__kvm_nvhe___hyp_stub_vectors		= __hyp_stub_vectors;
+__kvm_nvhe_idmap_t0sz			= idmap_t0sz;
+
+/* Alternative callbacks, referenced in .altinstructions. Executed in EL1. */
+__kvm_nvhe_arm64_enable_wa2_handling	= arm64_enable_wa2_handling;
+__kvm_nvhe_kvm_patch_vector_branch	= kvm_patch_vector_branch;
+__kvm_nvhe_kvm_update_va_mask		= kvm_update_va_mask;
+
+/* Values used to convert between memory mappings, read-only after init. */
+__kvm_nvhe_kimage_voffset		= kimage_voffset;
+
+/* Data shared with the kernel. */
+__kvm_nvhe_cpu_hwcaps			= cpu_hwcaps;
+__kvm_nvhe_cpu_hwcap_keys		= cpu_hwcap_keys;
+__kvm_nvhe___icache_flags		= __icache_flags;
+__kvm_nvhe_kvm_vgic_global_state	= kvm_vgic_global_state;
+__kvm_nvhe_arm64_ssbd_callback_required	= arm64_ssbd_callback_required;
+__kvm_nvhe_kvm_host_data		= kvm_host_data;
+
+/* Static keys shared with the kernel. */
+__kvm_nvhe_arm64_const_caps_ready	= arm64_const_caps_ready;
 #ifdef CONFIG_ARM64_PSEUDO_NMI
-__kvm_nvhe_gic_pmr_sync = gic_pmr_sync;
+__kvm_nvhe_gic_pmr_sync			= gic_pmr_sync;
 #endif
-__kvm_nvhe_idmap_t0sz = idmap_t0sz;
-__kvm_nvhe_kimage_voffset = kimage_voffset;
-__kvm_nvhe_kvm_host_data = kvm_host_data;
-__kvm_nvhe_kvm_patch_vector_branch = kvm_patch_vector_branch;
-__kvm_nvhe_kvm_update_va_mask = kvm_update_va_mask;
-__kvm_nvhe_kvm_vgic_global_state = kvm_vgic_global_state;
-__kvm_nvhe_panic = panic;
+__kvm_nvhe_vgic_v2_cpuif_trap		= vgic_v2_cpuif_trap;
+__kvm_nvhe_vgic_v3_cpuif_trap		= vgic_v3_cpuif_trap;
+
+/* SVE support, currently unused by nVHE. */
 #ifdef CONFIG_ARM64_SVE
-__kvm_nvhe_sve_load_state = sve_load_state;
-__kvm_nvhe_sve_save_state = sve_save_state;
+__kvm_nvhe_sve_save_state		= sve_save_state;
+__kvm_nvhe_sve_load_state		= sve_load_state;
 #endif
-__kvm_nvhe_vgic_v2_cpuif_trap = vgic_v2_cpuif_trap;
-__kvm_nvhe_vgic_v3_cpuif_trap = vgic_v3_cpuif_trap;
 
 #endif /* CONFIG_KVM */
 
-- 
2.27.0