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| author | James Morse <james.morse@arm.com> | 2020-08-21 17:07:05 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2020-08-28 17:23:42 +0300 |
| commit | e9ee186bb735bfc17fa81dbc9aebf268aee5b41e (patch) | |
| tree | 2691a94dbb362cecc47361363cffc7746317d51f /arch/arm64/kvm/hyp/include | |
| parent | 5d28ba5f8a0cfa3a874fa96c33731b8fcd141b3a (diff) | |
| download | linux-e9ee186bb735bfc17fa81dbc9aebf268aee5b41e.tar.xz | |
KVM: arm64: Add kvm_extable for vaxorcism code
KVM has a one instruction window where it will allow an SError exception
to be consumed by the hypervisor without treating it as a hypervisor bug.
This is used to consume asynchronous external abort that were caused by
the guest.
As we are about to add another location that survives unexpected exceptions,
generalise this code to make it behave like the host's extable.
KVM's version has to be mapped to EL2 to be accessible on nVHE systems.
The SError vaxorcism code is a one instruction window, so has two entries
in the extable. Because the KVM code is copied for VHE and nVHE, we end up
with four entries, half of which correspond with code that isn't mapped.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'arch/arm64/kvm/hyp/include')
| -rw-r--r-- | arch/arm64/kvm/hyp/include/hyp/switch.h | 31 |
1 files changed, 31 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index 426ef65601dd..6d8d4ed4287c 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -17,6 +17,7 @@ #include <asm/barrier.h> #include <asm/cpufeature.h> +#include <asm/extable.h> #include <asm/kprobes.h> #include <asm/kvm_asm.h> #include <asm/kvm_emulate.h> @@ -29,6 +30,9 @@ extern const char __hyp_panic_string[]; +extern struct exception_table_entry __start___kvm_ex_table; +extern struct exception_table_entry __stop___kvm_ex_table; + /* Check whether the FP regs were dirtied while in the host-side run loop: */ static inline bool update_fp_enabled(struct kvm_vcpu *vcpu) { @@ -508,4 +512,31 @@ static inline void __set_host_arch_workaround_state(struct kvm_vcpu *vcpu) #endif } +static inline void __kvm_unexpected_el2_exception(void) +{ + unsigned long addr, fixup; + struct kvm_cpu_context *host_ctxt; + struct exception_table_entry *entry, *end; + unsigned long elr_el2 = read_sysreg(elr_el2); + + entry = hyp_symbol_addr(__start___kvm_ex_table); + end = hyp_symbol_addr(__stop___kvm_ex_table); + host_ctxt = &__hyp_this_cpu_ptr(kvm_host_data)->host_ctxt; + + while (entry < end) { + addr = (unsigned long)&entry->insn + entry->insn; + fixup = (unsigned long)&entry->fixup + entry->fixup; + + if (addr != elr_el2) { + entry++; + continue; + } + + write_sysreg(fixup, elr_el2); + return; + } + + hyp_panic(host_ctxt); +} + #endif /* __ARM64_KVM_HYP_SWITCH_H__ */ |