Commit c97e166e authored by James Morse's avatar James Morse Committed by Catalin Marinas

KVM: arm64: Change hyp_panic()s dependency on tpidr_el2

Make tpidr_el2 a cpu-offset for per-cpu variables in the same way the
host uses tpidr_el1. This lets tpidr_el{1,2} have the same value, and
on VHE they can be the same register.

KVM calls hyp_panic() when anything unexpected happens. This may occur
while a guest owns the EL1 registers. KVM stashes the vcpu pointer in
tpidr_el2, which it uses to find the host context in order to restore
the host EL1 registers before parachuting into the host's panic().

The host context is a struct kvm_cpu_context allocated in the per-cpu
area, and mapped to hyp. Given the per-cpu offset for this CPU, this is
easy to find. Change hyp_panic() to take a pointer to the
struct kvm_cpu_context. Wrap these calls with an asm function that
retrieves the struct kvm_cpu_context from the host's per-cpu area.

Copy the per-cpu offset from the hosts tpidr_el1 into tpidr_el2 during
kvm init. (Later patches will make this unnecessary for VHE hosts)

We print out the vcpu pointer as part of the panic message. Add a back
reference to the 'running vcpu' in the host cpu context to preserve this.
Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Reviewed-by: default avatarChristoffer Dall <cdall@linaro.org>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 36989e7f
......@@ -192,6 +192,8 @@ struct kvm_cpu_context {
u64 sys_regs[NR_SYS_REGS];
u32 copro[NR_COPRO_REGS];
};
struct kvm_vcpu *__hyp_running_vcpu;
};
typedef struct kvm_cpu_context kvm_cpu_context_t;
......
......@@ -163,6 +163,18 @@ ENTRY(__hyp_do_panic)
eret
ENDPROC(__hyp_do_panic)
ENTRY(__hyp_panic)
/*
* '=kvm_host_cpu_state' is a host VA from the constant pool, it may
* not be accessible by this address from EL2, hyp_panic() converts
* it with kern_hyp_va() before use.
*/
ldr x0, =kvm_host_cpu_state
mrs x1, tpidr_el2
add x0, x0, x1
b hyp_panic
ENDPROC(__hyp_panic)
.macro invalid_vector label, target = __hyp_panic
.align 2
\label:
......
......@@ -86,5 +86,8 @@ u32 __hyp_text __init_stage2_translation(void)
write_sysreg(val, vtcr_el2);
/* copy tpidr_el1 into tpidr_el2 for use by HYP */
write_sysreg(read_sysreg(tpidr_el1), tpidr_el2);
return parange;
}
......@@ -306,9 +306,9 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu)
u64 exit_code;
vcpu = kern_hyp_va(vcpu);
write_sysreg(vcpu, tpidr_el2);
host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
host_ctxt->__hyp_running_vcpu = vcpu;
guest_ctxt = &vcpu->arch.ctxt;
__sysreg_save_host_state(host_ctxt);
......@@ -443,7 +443,8 @@ int __hyp_text __kvm_vcpu_run(struct kvm_vcpu *vcpu)
static const char __hyp_panic_string[] = "HYP panic:\nPS:%08llx PC:%016llx ESR:%08llx\nFAR:%016llx HPFAR:%016llx PAR:%016llx\nVCPU:%p\n";
static void __hyp_text __hyp_call_panic_nvhe(u64 spsr, u64 elr, u64 par)
static void __hyp_text __hyp_call_panic_nvhe(u64 spsr, u64 elr, u64 par,
struct kvm_vcpu *vcpu)
{
unsigned long str_va;
......@@ -457,35 +458,35 @@ static void __hyp_text __hyp_call_panic_nvhe(u64 spsr, u64 elr, u64 par)
__hyp_do_panic(str_va,
spsr, elr,
read_sysreg(esr_el2), read_sysreg_el2(far),
read_sysreg(hpfar_el2), par,
(void *)read_sysreg(tpidr_el2));
read_sysreg(hpfar_el2), par, vcpu);
}
static void __hyp_text __hyp_call_panic_vhe(u64 spsr, u64 elr, u64 par)
static void __hyp_text __hyp_call_panic_vhe(u64 spsr, u64 elr, u64 par,
struct kvm_vcpu *vcpu)
{
panic(__hyp_panic_string,
spsr, elr,
read_sysreg_el2(esr), read_sysreg_el2(far),
read_sysreg(hpfar_el2), par,
(void *)read_sysreg(tpidr_el2));
read_sysreg(hpfar_el2), par, vcpu);
}
static hyp_alternate_select(__hyp_call_panic,
__hyp_call_panic_nvhe, __hyp_call_panic_vhe,
ARM64_HAS_VIRT_HOST_EXTN);
void __hyp_text __noreturn __hyp_panic(void)
void __hyp_text __noreturn hyp_panic(struct kvm_cpu_context *__host_ctxt)
{
struct kvm_vcpu *vcpu = NULL;
u64 spsr = read_sysreg_el2(spsr);
u64 elr = read_sysreg_el2(elr);
u64 par = read_sysreg(par_el1);
if (read_sysreg(vttbr_el2)) {
struct kvm_vcpu *vcpu;
struct kvm_cpu_context *host_ctxt;
vcpu = (struct kvm_vcpu *)read_sysreg(tpidr_el2);
host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
host_ctxt = kern_hyp_va(__host_ctxt);
vcpu = host_ctxt->__hyp_running_vcpu;
__timer_disable_traps(vcpu);
__deactivate_traps(vcpu);
__deactivate_vm(vcpu);
......@@ -493,7 +494,7 @@ void __hyp_text __noreturn __hyp_panic(void)
}
/* Call panic for real */
__hyp_call_panic()(spsr, elr, par);
__hyp_call_panic()(spsr, elr, par, vcpu);
unreachable();
}
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