KVM: arm64: Drop the CPU_FTR_REG_HYP_COPY infrastructure

Now that the read_ctr macro has been specialised for nVHE,
the whole CPU_FTR_REG_HYP_COPY infrastrcture looks completely
overengineered.

Simplify it by populating the two u64 quantities (MMFR0 and 1)
that the hypervisor need.

Reviewed-by: Quentin Perret <qperret@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>

diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index a85cea2cac573a4fa98bbb0b30c9c6c19319c4fd..61177bac49fa7fe7831c381598708a3946a868fe 100644 (file)
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -607,7 +607,6 @@ void check_local_cpu_capabilities(void);
 
 u64 read_sanitised_ftr_reg(u32 id);
 u64 __read_sysreg_by_encoding(u32 sys_id);
-int copy_ftr_reg(u32 id, struct arm64_ftr_reg *dst);
 
 static inline bool cpu_supports_mixed_endian_el0(void)
 {

diff --git a/arch/arm64/include/asm/kvm_cpufeature.h b/arch/arm64/include/asm/kvm_cpufeature.h
deleted file mode 100644 (file)
index ff302d1..0000000
--- a/arch/arm64/include/asm/kvm_cpufeature.h
+++ /dev/null
@@ -1,26 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copyright (C) 2020 - Google LLC
- * Author: Quentin Perret <qperret@google.com>
- */
-
-#ifndef __ARM64_KVM_CPUFEATURE_H__
-#define __ARM64_KVM_CPUFEATURE_H__
-
-#include <asm/cpufeature.h>
-
-#include <linux/build_bug.h>
-
-#if defined(__KVM_NVHE_HYPERVISOR__)
-#define DECLARE_KVM_HYP_CPU_FTR_REG(name) extern struct arm64_ftr_reg name
-#define DEFINE_KVM_HYP_CPU_FTR_REG(name) struct arm64_ftr_reg name
-#else
-#define DECLARE_KVM_HYP_CPU_FTR_REG(name) extern struct arm64_ftr_reg kvm_nvhe_sym(name)
-#define DEFINE_KVM_HYP_CPU_FTR_REG(name) BUILD_BUG()
-#endif
-
-DECLARE_KVM_HYP_CPU_FTR_REG(arm64_ftr_reg_ctrel0);
-DECLARE_KVM_HYP_CPU_FTR_REG(arm64_ftr_reg_id_aa64mmfr0_el1);
-DECLARE_KVM_HYP_CPU_FTR_REG(arm64_ftr_reg_id_aa64mmfr1_el1);
-
-#endif

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 4859c9de75d7c2e23510e32f883090194e349134..09979cdec28bda235937b9f3f5d2dfff2f934a96 100644 (file)
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -740,13 +740,9 @@ void kvm_clr_pmu_events(u32 clr);
 
 void kvm_vcpu_pmu_restore_guest(struct kvm_vcpu *vcpu);
 void kvm_vcpu_pmu_restore_host(struct kvm_vcpu *vcpu);
-
-void setup_kvm_el2_caps(void);
 #else
 static inline void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr) {}
 static inline void kvm_clr_pmu_events(u32 clr) {}
-
-static inline void setup_kvm_el2_caps(void) {}
 #endif
 
 void kvm_vcpu_load_sysregs_vhe(struct kvm_vcpu *vcpu);

diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h
index de40a565d7e5e214e782cd12a721f60238f5d913..8ef9d88826d45552a4cdfe859d006e4df4cef950 100644 (file)
--- a/arch/arm64/include/asm/kvm_hyp.h
+++ b/arch/arm64/include/asm/kvm_hyp.h
@@ -116,4 +116,7 @@ int __pkvm_init(phys_addr_t phys, unsigned long size, unsigned long nr_cpus,
 void __noreturn __host_enter(struct kvm_cpu_context *host_ctxt);
 #endif
 
+extern u64 kvm_nvhe_sym(id_aa64mmfr0_el1_sys_val);
+extern u64 kvm_nvhe_sym(id_aa64mmfr1_el1_sys_val);
+
 #endif /* __ARM64_KVM_HYP_H__ */

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 6252476e4e73b08d296730c0a1c8552b2f3faf3a..066030717a4c7f4c555659eeeb362871f25b7583 100644 (file)
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1154,18 +1154,6 @@ u64 read_sanitised_ftr_reg(u32 id)
 }
 EXPORT_SYMBOL_GPL(read_sanitised_ftr_reg);
 
-int copy_ftr_reg(u32 id, struct arm64_ftr_reg *dst)
-{
-       struct arm64_ftr_reg *regp = get_arm64_ftr_reg(id);
-
-       if (!regp)
-               return -EINVAL;
-
-       *dst = *regp;
-
-       return 0;
-}
-
 #define read_sysreg_case(r)    \
        case r:         val = read_sysreg_s(r); break;
 
@@ -2785,7 +2773,6 @@ void __init setup_cpu_features(void)
 
        setup_system_capabilities();
        setup_elf_hwcaps(arm64_elf_hwcaps);
-       setup_kvm_el2_caps();
 
        if (system_supports_32bit_el0())
                setup_elf_hwcaps(compat_elf_hwcaps);

diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 368159021dee4df7e8c031621a3efa0bd736376d..2835400fd298eb09de1024987e67b5430f1fda69 100644 (file)
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -1730,6 +1730,9 @@ static int kvm_hyp_init_protection(u32 hyp_va_bits)
        void *addr = phys_to_virt(hyp_mem_base);
        int ret;
 
+       kvm_nvhe_sym(id_aa64mmfr0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1);
+       kvm_nvhe_sym(id_aa64mmfr1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1);
+
        ret = create_hyp_mappings(addr, addr + hyp_mem_size, PAGE_HYP);
        if (ret)
                return ret;

diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-smp.c b/arch/arm64/kvm/hyp/nvhe/hyp-smp.c
index 17ad1b3a9530f9694c413a3d87d76233ae1ac525..879559057dee0036c6e8b17599639eb11e374ec2 100644 (file)
--- a/arch/arm64/kvm/hyp/nvhe/hyp-smp.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-smp.c
@@ -5,17 +5,9 @@
  */
 
 #include <asm/kvm_asm.h>
-#include <asm/kvm_cpufeature.h>
 #include <asm/kvm_hyp.h>
 #include <asm/kvm_mmu.h>
 
-/*
- * Copies of the host's CPU features registers holding sanitized values.
- */
-DEFINE_KVM_HYP_CPU_FTR_REG(arm64_ftr_reg_ctrel0);
-DEFINE_KVM_HYP_CPU_FTR_REG(arm64_ftr_reg_id_aa64mmfr0_el1);
-DEFINE_KVM_HYP_CPU_FTR_REG(arm64_ftr_reg_id_aa64mmfr1_el1);
-
 /*
  * nVHE copy of data structures tracking available CPU cores.
  * Only entries for CPUs that were online at KVM init are populated.

diff --git a/arch/arm64/kvm/hyp/nvhe/mem_protect.c b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
index 808e2471091bf6f40381868aa99714be336ee3e1..f4f364aa3282b37e9262dfe110d3cf71b63b6ba9 100644 (file)
--- a/arch/arm64/kvm/hyp/nvhe/mem_protect.c
+++ b/arch/arm64/kvm/hyp/nvhe/mem_protect.c
@@ -5,7 +5,6 @@
  */
 
 #include <linux/kvm_host.h>
-#include <asm/kvm_cpufeature.h>
 #include <asm/kvm_emulate.h>
 #include <asm/kvm_hyp.h>
 #include <asm/kvm_mmu.h>
@@ -27,6 +26,12 @@ struct host_kvm host_kvm;
 struct hyp_pool host_s2_mem;
 struct hyp_pool host_s2_dev;
 
+/*
+ * Copies of the host's CPU features registers holding sanitized values.
+ */
+u64 id_aa64mmfr0_el1_sys_val;
+u64 id_aa64mmfr1_el1_sys_val;
+
 static const u8 pkvm_hyp_id = 1;
 
 static void *host_s2_zalloc_pages_exact(size_t size)
@@ -72,16 +77,13 @@ static int prepare_s2_pools(void *mem_pgt_pool, void *dev_pgt_pool)
 static void prepare_host_vtcr(void)
 {
        u32 parange, phys_shift;
-       u64 mmfr0, mmfr1;
-
-       mmfr0 = arm64_ftr_reg_id_aa64mmfr0_el1.sys_val;
-       mmfr1 = arm64_ftr_reg_id_aa64mmfr1_el1.sys_val;
 
        /* The host stage 2 is id-mapped, so use parange for T0SZ */
-       parange = kvm_get_parange(mmfr0);
+       parange = kvm_get_parange(id_aa64mmfr0_el1_sys_val);
        phys_shift = id_aa64mmfr0_parange_to_phys_shift(parange);
 
-       host_kvm.arch.vtcr = kvm_get_vtcr(mmfr0, mmfr1, phys_shift);
+       host_kvm.arch.vtcr = kvm_get_vtcr(id_aa64mmfr0_el1_sys_val,
+                                         id_aa64mmfr1_el1_sys_val, phys_shift);
 }
 
 int kvm_host_prepare_stage2(void *mem_pgt_pool, void *dev_pgt_pool)

diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index dfb3b4f9ca848a4f8707e9075152e16b5cc56ba5..4f2f1e3145debfc90ba0d358eb769e1300539ce8 100644 (file)
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -21,7 +21,6 @@
 #include <asm/debug-monitors.h>
 #include <asm/esr.h>
 #include <asm/kvm_arm.h>
-#include <asm/kvm_cpufeature.h>
 #include <asm/kvm_emulate.h>
 #include <asm/kvm_hyp.h>
 #include <asm/kvm_mmu.h>
@@ -2776,24 +2775,3 @@ void kvm_sys_reg_table_init(void)
        /* Clear all higher bits. */
        cache_levels &= (1 << (i*3))-1;
 }
-
-#define CPU_FTR_REG_HYP_COPY(id, name) \
-       { .sys_id = id, .dst = (struct arm64_ftr_reg *)&kvm_nvhe_sym(name) }
-struct __ftr_reg_copy_entry {
-       u32                     sys_id;
-       struct arm64_ftr_reg    *dst;
-} hyp_ftr_regs[] __initdata = {
-       CPU_FTR_REG_HYP_COPY(SYS_CTR_EL0, arm64_ftr_reg_ctrel0),
-       CPU_FTR_REG_HYP_COPY(SYS_ID_AA64MMFR0_EL1, arm64_ftr_reg_id_aa64mmfr0_el1),
-       CPU_FTR_REG_HYP_COPY(SYS_ID_AA64MMFR1_EL1, arm64_ftr_reg_id_aa64mmfr1_el1),
-};
-
-void __init setup_kvm_el2_caps(void)
-{
-       int i;
-
-       for (i = 0; i < ARRAY_SIZE(hyp_ftr_regs); i++) {
-               WARN(copy_ftr_reg(hyp_ftr_regs[i].sys_id, hyp_ftr_regs[i].dst),
-                    "%u feature register not found\n", hyp_ftr_regs[i].sys_id);
-       }
-}