* [PATCH v2 1/3] KVM: arm64: Constraint KVM's own __flush_dcache_area to protectected mode
2021-03-22 17:56 [PATCH v2 0/3] KVM:arm64: Proposed host stage-2 improvements Marc Zyngier
@ 2021-03-22 17:56 ` Marc Zyngier
2021-03-22 17:56 ` [PATCH v2 2/3] KVM: arm64: Generate final CTR_EL0 value when running in Protected mode Marc Zyngier
2021-03-22 17:56 ` [PATCH v2 3/3] KVM: arm64: Drop the CPU_FTR_REG_HYP_COPY infrastructure Marc Zyngier
2 siblings, 0 replies; 5+ messages in thread
From: Marc Zyngier @ 2021-03-22 17:56 UTC (permalink / raw)
To: Quentin Perret
Cc: catalin.marinas, james.morse, julien.thierry.kdev,
suzuki.poulose, android-kvm, seanjc, mate.toth-pal, linux-kernel,
linux-arm-kernel, kernel-team, kvmarm, tabba, ardb, mark.rutland,
dbrazdil
As we are about to specialise KVM's version of __flush_dcache_area
via a hack on the read_ctr macro, make sure that we won't ever
use KVM's copy of __flush_dcache_area(), as things would otherwise
break for late arriving CPUs.
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/hyp/nvhe/cache.S | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/arm64/kvm/hyp/nvhe/cache.S b/arch/arm64/kvm/hyp/nvhe/cache.S
index 36cef6915428..1c177d3ec5c6 100644
--- a/arch/arm64/kvm/hyp/nvhe/cache.S
+++ b/arch/arm64/kvm/hyp/nvhe/cache.S
@@ -6,8 +6,12 @@
#include <linux/linkage.h>
#include <asm/assembler.h>
#include <asm/alternative.h>
+#include <asm/asm-bug.h>
SYM_FUNC_START_PI(__flush_dcache_area)
+alternative_if_not ARM64_KVM_PROTECTED_MODE
+ ASM_BUG()
+alternative_else_nop_endif
dcache_by_line_op civac, sy, x0, x1, x2, x3
ret
SYM_FUNC_END_PI(__flush_dcache_area)
--
2.29.2
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v2 2/3] KVM: arm64: Generate final CTR_EL0 value when running in Protected mode
2021-03-22 17:56 [PATCH v2 0/3] KVM:arm64: Proposed host stage-2 improvements Marc Zyngier
2021-03-22 17:56 ` [PATCH v2 1/3] KVM: arm64: Constraint KVM's own __flush_dcache_area to protectected mode Marc Zyngier
@ 2021-03-22 17:56 ` Marc Zyngier
2021-03-22 17:56 ` [PATCH v2 3/3] KVM: arm64: Drop the CPU_FTR_REG_HYP_COPY infrastructure Marc Zyngier
2 siblings, 0 replies; 5+ messages in thread
From: Marc Zyngier @ 2021-03-22 17:56 UTC (permalink / raw)
To: Quentin Perret
Cc: catalin.marinas, james.morse, julien.thierry.kdev,
suzuki.poulose, android-kvm, seanjc, mate.toth-pal, linux-kernel,
linux-arm-kernel, kernel-team, kvmarm, tabba, ardb, mark.rutland,
dbrazdil
In protected mode, late CPUs are not allowed to boot (enforced by
the PSCI relay). We can thus specialise the read_ctr macro to
always return a pre-computed, sanitised value.
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/include/asm/assembler.h | 9 +++++++++
arch/arm64/kernel/image-vars.h | 1 +
arch/arm64/kvm/va_layout.c | 7 +++++++
3 files changed, 17 insertions(+)
diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index fb651c1f26e9..1a4cee7eb3c9 100644
--- a/arch/arm64/include/asm/assembler.h
+++ b/arch/arm64/include/asm/assembler.h
@@ -270,12 +270,21 @@ alternative_endif
* provide the system wide safe value from arm64_ftr_reg_ctrel0.sys_val
*/
.macro read_ctr, reg
+#ifndef __KVM_NVHE_HYPERVISOR__
alternative_if_not ARM64_MISMATCHED_CACHE_TYPE
mrs \reg, ctr_el0 // read CTR
nop
alternative_else
ldr_l \reg, arm64_ftr_reg_ctrel0 + ARM64_FTR_SYSVAL
alternative_endif
+#else
+alternative_cb kvm_compute_final_ctr_el0
+ movz \reg, #0
+ movk \reg, #0, lsl #16
+ movk \reg, #0, lsl #32
+ movk \reg, #0, lsl #48
+alternative_cb_end
+#endif
.endm
diff --git a/arch/arm64/kernel/image-vars.h b/arch/arm64/kernel/image-vars.h
index d5dc2b792651..fdd60cd1d7e8 100644
--- a/arch/arm64/kernel/image-vars.h
+++ b/arch/arm64/kernel/image-vars.h
@@ -65,6 +65,7 @@ __efistub__ctype = _ctype;
KVM_NVHE_ALIAS(kvm_patch_vector_branch);
KVM_NVHE_ALIAS(kvm_update_va_mask);
KVM_NVHE_ALIAS(kvm_get_kimage_voffset);
+KVM_NVHE_ALIAS(kvm_compute_final_ctr_el0);
/* Global kernel state accessed by nVHE hyp code. */
KVM_NVHE_ALIAS(kvm_vgic_global_state);
diff --git a/arch/arm64/kvm/va_layout.c b/arch/arm64/kvm/va_layout.c
index 978301392d67..acdb7b3cc97d 100644
--- a/arch/arm64/kvm/va_layout.c
+++ b/arch/arm64/kvm/va_layout.c
@@ -288,3 +288,10 @@ void kvm_get_kimage_voffset(struct alt_instr *alt,
{
generate_mov_q(kimage_voffset, origptr, updptr, nr_inst);
}
+
+void kvm_compute_final_ctr_el0(struct alt_instr *alt,
+ __le32 *origptr, __le32 *updptr, int nr_inst)
+{
+ generate_mov_q(read_sanitised_ftr_reg(SYS_CTR_EL0),
+ origptr, updptr, nr_inst);
+}
--
2.29.2
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v2 3/3] KVM: arm64: Drop the CPU_FTR_REG_HYP_COPY infrastructure
2021-03-22 17:56 [PATCH v2 0/3] KVM:arm64: Proposed host stage-2 improvements Marc Zyngier
2021-03-22 17:56 ` [PATCH v2 1/3] KVM: arm64: Constraint KVM's own __flush_dcache_area to protectected mode Marc Zyngier
2021-03-22 17:56 ` [PATCH v2 2/3] KVM: arm64: Generate final CTR_EL0 value when running in Protected mode Marc Zyngier
@ 2021-03-22 17:56 ` Marc Zyngier
2021-03-23 9:47 ` Quentin Perret
2 siblings, 1 reply; 5+ messages in thread
From: Marc Zyngier @ 2021-03-22 17:56 UTC (permalink / raw)
To: Quentin Perret
Cc: catalin.marinas, james.morse, julien.thierry.kdev,
suzuki.poulose, android-kvm, seanjc, mate.toth-pal, linux-kernel,
linux-arm-kernel, kernel-team, kvmarm, tabba, ardb, mark.rutland,
dbrazdil
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.
Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/include/asm/cpufeature.h | 1 -
arch/arm64/include/asm/kvm_cpufeature.h | 26 -------------------------
arch/arm64/include/asm/kvm_host.h | 4 ----
arch/arm64/include/asm/kvm_hyp.h | 3 +++
arch/arm64/kernel/cpufeature.c | 13 -------------
arch/arm64/kvm/arm.c | 3 +++
arch/arm64/kvm/hyp/nvhe/hyp-smp.c | 8 --------
arch/arm64/kvm/hyp/nvhe/mem_protect.c | 16 ++++++++-------
arch/arm64/kvm/sys_regs.c | 22 ---------------------
9 files changed, 15 insertions(+), 81 deletions(-)
delete mode 100644 arch/arm64/include/asm/kvm_cpufeature.h
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index a85cea2cac57..61177bac49fa 100644
--- 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
index ff302d15e840..000000000000
--- 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 4859c9de75d7..09979cdec28b 100644
--- 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 de40a565d7e5..8ef9d88826d4 100644
--- 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 6252476e4e73..066030717a4c 100644
--- 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 368159021dee..2835400fd298 100644
--- 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 17ad1b3a9530..879559057dee 100644
--- 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 808e2471091b..f4f364aa3282 100644
--- 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 dfb3b4f9ca84..4f2f1e3145de 100644
--- 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);
- }
-}
--
2.29.2
^ permalink raw reply related [flat|nested] 5+ messages in thread