Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge branch kvm-arm64/pkvm-psci into kvmarm-master/next
* kvm-arm64/pkvm-psci:
: .
: Cleanup of the pKVM PSCI relay CPU entry code, making it slightly
: easier to follow, should someone have to wade into these waters
: ever again.
: .
KVM: arm64: Remove extra ISBs when using msr_hcr_el2
KVM: arm64: pkvm: Use direct function pointers for cpu_{on,resume}
KVM: arm64: pkvm: Turn __kvm_hyp_init_cpu into an inner label
KVM: arm64: pkvm: Simplify BTI handling on CPU boot
KVM: arm64: pkvm: Move error handling to the end of kvm_hyp_cpu_entry
Signed-off-by: Marc Zyngier <maz@kernel.org>
+43
-59
-2
arch/arm64/include/asm/el2_setup.h
-2
arch/arm64/include/asm/el2_setup.h
+2
-1
arch/arm64/include/asm/kvm_asm.h
+2
-1
arch/arm64/include/asm/kvm_asm.h
···
301
301
asmlinkage void kvm_unexpected_el2_exception(void);
302
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struct kvm_cpu_context;
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303
void handle_trap(struct kvm_cpu_context *host_ctxt);
304
-
asmlinkage void __noreturn __kvm_host_psci_cpu_entry(bool is_cpu_on);
304
+
asmlinkage void __noreturn __kvm_host_psci_cpu_on_entry(void);
305
+
asmlinkage void __noreturn __kvm_host_psci_cpu_resume_entry(void);
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void __noreturn __pkvm_init_finalise(void);
306
307
void kvm_nvhe_prepare_backtrace(unsigned long fp, unsigned long pc);
307
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void kvm_patch_vector_branch(struct alt_instr *alt,
+2
-4
arch/arm64/include/asm/sysreg.h
+2
-4
arch/arm64/include/asm/sysreg.h
···
1121
1121
.macro msr_hcr_el2, reg
1122
1122
#if IS_ENABLED(CONFIG_AMPERE_ERRATUM_AC04_CPU_23)
1123
1123
dsb nsh
1124
-
msr hcr_el2, \reg
1125
-
isb
1126
-
#else
1127
-
msr hcr_el2, \reg
1128
1124
#endif
1125
+
msr hcr_el2, \reg
1126
+
isb // Required by AMPERE_ERRATUM_AC04_CPU_23
1129
1127
.endm
1130
1128
#else
1131
1129
-1
arch/arm64/kernel/hyp-stub.S
-1
arch/arm64/kernel/hyp-stub.S
-11
arch/arm64/kvm/hyp/nvhe/host.S
-11
arch/arm64/kvm/hyp/nvhe/host.S
···
125
125
mrs x0, hcr_el2
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bic x0, x0, #HCR_VM
127
127
msr_hcr_el2 x0
128
-
isb
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128
tlbi vmalls12e1
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129
dsb nsh
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130
#endif
···
290
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ret
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SYM_CODE_END(__kvm_hyp_host_forward_smc)
293
-
294
-
/*
295
-
* kvm_host_psci_cpu_entry is called through br instruction, which requires
296
-
* bti j instruction as compilers (gcc and llvm) doesn't insert bti j for external
297
-
* functions, but bti c instead.
298
-
*/
299
-
SYM_CODE_START(kvm_host_psci_cpu_entry)
300
-
bti j
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-
b __kvm_host_psci_cpu_entry
302
-
SYM_CODE_END(kvm_host_psci_cpu_entry)
+15
-26
arch/arm64/kvm/hyp/nvhe/hyp-init.S
+15
-26
arch/arm64/kvm/hyp/nvhe/hyp-init.S
···
173
173
* x0: struct kvm_nvhe_init_params PA
174
174
*/
175
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SYM_CODE_START(kvm_hyp_cpu_entry)
176
-
mov x1, #1 // is_cpu_on = true
176
+
ldr x29, =__kvm_host_psci_cpu_on_entry
177
177
b __kvm_hyp_init_cpu
178
-
SYM_CODE_END(kvm_hyp_cpu_entry)
179
178
180
179
/*
181
180
* PSCI CPU_SUSPEND / SYSTEM_SUSPEND entry point
···
182
183
* x0: struct kvm_nvhe_init_params PA
183
184
*/
184
185
SYM_CODE_START(kvm_hyp_cpu_resume)
185
-
mov x1, #0 // is_cpu_on = false
186
-
b __kvm_hyp_init_cpu
187
-
SYM_CODE_END(kvm_hyp_cpu_resume)
186
+
ldr x29, =__kvm_host_psci_cpu_resume_entry
188
187
189
-
/*
190
-
* Common code for CPU entry points. Initializes EL2 state and
191
-
* installs the hypervisor before handing over to a C handler.
192
-
*
193
-
* x0: struct kvm_nvhe_init_params PA
194
-
* x1: bool is_cpu_on
195
-
*/
196
-
SYM_CODE_START_LOCAL(__kvm_hyp_init_cpu)
188
+
SYM_INNER_LABEL(__kvm_hyp_init_cpu, SYM_L_LOCAL)
197
189
mov x28, x0 // Stash arguments
198
-
mov x29, x1
199
190
200
191
/* Check that the core was booted in EL2. */
201
192
mrs x0, CurrentEL
202
193
cmp x0, #CurrentEL_EL2
203
-
b.eq 2f
194
+
b.ne 1f
204
195
205
-
/* The core booted in EL1. KVM cannot be initialized on it. */
206
-
1: wfe
207
-
wfi
208
-
b 1b
209
-
210
-
2: msr SPsel, #1 // We want to use SP_EL{1,2}
196
+
msr SPsel, #1 // We want to use SP_EL2
211
197
212
198
init_el2_hcr 0
213
199
···
202
218
mov x0, x28
203
219
bl ___kvm_hyp_init // Clobbers x0..x2
204
220
205
-
/* Leave idmap. */
206
-
mov x0, x29
207
-
ldr x1, =kvm_host_psci_cpu_entry
208
-
br x1
209
-
SYM_CODE_END(__kvm_hyp_init_cpu)
221
+
/* Leave idmap -- using BLR is OK, LR is restored from host context */
222
+
blr x29
223
+
224
+
// The core booted in EL1, or the C code unexpectedly returned.
225
+
// Either way, KVM cannot be initialized on it.
226
+
1: wfe
227
+
wfi
228
+
b 1b
229
+
SYM_CODE_END(kvm_hyp_cpu_resume)
230
+
SYM_CODE_END(kvm_hyp_cpu_entry)
210
231
211
232
SYM_CODE_START(__kvm_handle_stub_hvc)
212
233
/*
+24
-14
arch/arm64/kvm/hyp/nvhe/psci-relay.c
+24
-14
arch/arm64/kvm/hyp/nvhe/psci-relay.c
···
201
201
__hyp_pa(init_params), 0);
202
202
}
203
203
204
-
asmlinkage void __noreturn __kvm_host_psci_cpu_entry(bool is_cpu_on)
204
+
static void __noreturn __kvm_host_psci_cpu_entry(unsigned long pc, unsigned long r0)
205
205
{
206
-
struct psci_boot_args *boot_args;
207
-
struct kvm_cpu_context *host_ctxt;
206
+
struct kvm_cpu_context *host_ctxt = host_data_ptr(host_ctxt);
208
207
209
-
host_ctxt = host_data_ptr(host_ctxt);
210
208
trace_hyp_enter(host_ctxt, HYP_REASON_PSCI);
211
209
212
-
if (is_cpu_on)
213
-
boot_args = this_cpu_ptr(&cpu_on_args);
214
-
else
215
-
boot_args = this_cpu_ptr(&suspend_args);
216
-
217
-
cpu_reg(host_ctxt, 0) = boot_args->r0;
218
-
write_sysreg_el2(boot_args->pc, SYS_ELR);
219
-
220
-
if (is_cpu_on)
221
-
release_boot_args(boot_args);
210
+
cpu_reg(host_ctxt, 0) = r0;
211
+
write_sysreg_el2(pc, SYS_ELR);
222
212
223
213
write_sysreg_el1(INIT_SCTLR_EL1_MMU_OFF, SYS_SCTLR);
224
214
write_sysreg(INIT_PSTATE_EL1, SPSR_EL2);
225
215
226
216
trace_hyp_exit(host_ctxt, HYP_REASON_PSCI);
227
217
__host_enter(host_ctxt);
218
+
}
219
+
220
+
asmlinkage void __noreturn __kvm_host_psci_cpu_on_entry(void)
221
+
{
222
+
struct psci_boot_args *boot_args = this_cpu_ptr(&cpu_on_args);
223
+
unsigned long pc, r0;
224
+
225
+
pc = READ_ONCE(boot_args->pc);
226
+
r0 = READ_ONCE(boot_args->r0);
227
+
228
+
release_boot_args(boot_args);
229
+
230
+
__kvm_host_psci_cpu_entry(pc, r0);
231
+
}
232
+
233
+
asmlinkage void __noreturn __kvm_host_psci_cpu_resume_entry(void)
234
+
{
235
+
struct psci_boot_args *boot_args = this_cpu_ptr(&suspend_args);
236
+
237
+
__kvm_host_psci_cpu_entry(boot_args->pc, boot_args->r0);
228
238
}
229
239
230
240
static unsigned long psci_0_1_handler(u64 func_id, struct kvm_cpu_context *host_ctxt)