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KVM: arm64: pkvm: Use direct function pointers for cpu_{on,resume}

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Instead of using a boolean to decide whether a CPU is booting or
resuming, just pass an actual function pointer around.

This makes the code a bit more straightforward to understand.

Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Link: https://patch.msgid.link/20260321212419.2803972-5-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
This commit is contained in:
Marc Zyngier 2026-03-21 21:24:18 +00:00
parent ba64e273ea
commit 59c6e12d40
3 changed files with 29 additions and 22 deletions
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3
arch/arm64/include/asm/kvm_asm.h
View File

@ -291,7 +291,8 @@ asmlinkage void __noreturn hyp_panic_bad_stack(void);
asmlinkage void kvm_unexpected_el2_exception(void);
struct kvm_cpu_context;
void handle_trap(struct kvm_cpu_context *host_ctxt);
asmlinkage void __noreturn __kvm_host_psci_cpu_entry(bool is_cpu_on);
asmlinkage void __noreturn __kvm_host_psci_cpu_on_entry(void);
asmlinkage void __noreturn __kvm_host_psci_cpu_resume_entry(void);
void __noreturn __pkvm_init_finalise(void);
void kvm_nvhe_prepare_backtrace(unsigned long fp, unsigned long pc);
void kvm_patch_vector_branch(struct alt_instr *alt,

9
arch/arm64/kvm/hyp/nvhe/hyp-init.S
View File

@ -173,7 +173,7 @@ SYM_CODE_END(___kvm_hyp_init)
* x0: struct kvm_nvhe_init_params PA
*/
SYM_CODE_START(kvm_hyp_cpu_entry)
mov x1, #1 // is_cpu_on = true
ldr x29, =__kvm_host_psci_cpu_on_entry
b __kvm_hyp_init_cpu
/*
@ -182,11 +182,10 @@ SYM_CODE_START(kvm_hyp_cpu_entry)
* x0: struct kvm_nvhe_init_params PA
*/
SYM_CODE_START(kvm_hyp_cpu_resume)
mov x1, #0 // is_cpu_on = false
ldr x29, =__kvm_host_psci_cpu_resume_entry
SYM_INNER_LABEL(__kvm_hyp_init_cpu, SYM_L_LOCAL)
mov x28, x0 // Stash arguments
mov x29, x1
/* Check that the core was booted in EL2. */
mrs x0, CurrentEL
@ -204,9 +203,7 @@ SYM_INNER_LABEL(__kvm_hyp_init_cpu, SYM_L_LOCAL)
bl ___kvm_hyp_init // Clobbers x0..x2
/* Leave idmap -- using BLR is OK, LR is restored from host context */
mov x0, x29
ldr x1, =__kvm_host_psci_cpu_entry
blr x1
blr x29
// The core booted in EL1, or the C code unexpectedly returned.
// Either way, KVM cannot be initialized on it.

39
arch/arm64/kvm/hyp/nvhe/psci-relay.c
View File

@ -200,23 +200,12 @@ static int psci_system_suspend(u64 func_id, struct kvm_cpu_context *host_ctxt)
__hyp_pa(init_params), 0);
}
asmlinkage void __noreturn __kvm_host_psci_cpu_entry(bool is_cpu_on)
static void __noreturn __kvm_host_psci_cpu_entry(unsigned long pc, unsigned long r0)
{
struct psci_boot_args *boot_args;
struct kvm_cpu_context *host_ctxt;
struct kvm_cpu_context *host_ctxt = host_data_ptr(host_ctxt);
host_ctxt = host_data_ptr(host_ctxt);
if (is_cpu_on)
boot_args = this_cpu_ptr(&cpu_on_args);
else
boot_args = this_cpu_ptr(&suspend_args);
cpu_reg(host_ctxt, 0) = boot_args->r0;
write_sysreg_el2(boot_args->pc, SYS_ELR);
if (is_cpu_on)
release_boot_args(boot_args);
cpu_reg(host_ctxt, 0) = r0;
write_sysreg_el2(pc, SYS_ELR);
write_sysreg_el1(INIT_SCTLR_EL1_MMU_OFF, SYS_SCTLR);
write_sysreg(INIT_PSTATE_EL1, SPSR_EL2);
@ -224,6 +213,26 @@ asmlinkage void __noreturn __kvm_host_psci_cpu_entry(bool is_cpu_on)
__host_enter(host_ctxt);
}
asmlinkage void __noreturn __kvm_host_psci_cpu_on_entry(void)
{
struct psci_boot_args *boot_args = this_cpu_ptr(&cpu_on_args);
unsigned long pc, r0;
pc = READ_ONCE(boot_args->pc);
r0 = READ_ONCE(boot_args->r0);
release_boot_args(boot_args);
__kvm_host_psci_cpu_entry(pc, r0);
}
asmlinkage void __noreturn __kvm_host_psci_cpu_resume_entry(void)
{
struct psci_boot_args *boot_args = this_cpu_ptr(&suspend_args);
__kvm_host_psci_cpu_entry(boot_args->pc, boot_args->r0);
}
static unsigned long psci_0_1_handler(u64 func_id, struct kvm_cpu_context *host_ctxt)
{
if (is_psci_0_1(cpu_off, func_id) || is_psci_0_1(migrate, func_id))