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| author | Marc Zyngier <marc.zyngier@arm.com> | 2019-01-19 16:29:54 +0100 |
|---|---|---|
| committer | Marc Zyngier <marc.zyngier@arm.com> | 2019-02-19 22:05:35 +0100 |
| commit | 32f139551954512bfdf9d558341af453bb8b12b4 (patch) | |
| tree | d7fc878ae67aab3ab2300b3ca72e51f03ff3482b /arch/arm64 | |
| parent | ARM: KVM: Teach some form of type-safety to kvm_call_hyp (diff) | |
| download | linux-32f139551954512bfdf9d558341af453bb8b12b4.tar.xz linux-32f139551954512bfdf9d558341af453bb8b12b4.zip | |
arm/arm64: KVM: Statically configure the host's view of MPIDR
We currently eagerly save/restore MPIDR. It turns out to be
slightly pointless:
- On the host, this value is known as soon as we're scheduled on a
physical CPU
- In the guest, this value cannot change, as it is set by KVM
(and this is a read-only register)
The result of the above is that we can perfectly avoid the eager
saving of MPIDR_EL1, and only keep the restore. We just have
to setup the host contexts appropriately at boot time.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
Diffstat (limited to 'arch/arm64')
| -rw-r--r-- | arch/arm64/include/asm/kvm_host.h | 8 | ||||
| -rw-r--r-- | arch/arm64/kvm/hyp/sysreg-sr.c | 1 |
2 files changed, 8 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 8b7702bdb219..f497bb31031f 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -30,6 +30,7 @@ #include <asm/kvm.h> #include <asm/kvm_asm.h> #include <asm/kvm_mmio.h> +#include <asm/smp_plat.h> #include <asm/thread_info.h> #define __KVM_HAVE_ARCH_INTC_INITIALIZED @@ -418,6 +419,13 @@ struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr); DECLARE_PER_CPU(kvm_cpu_context_t, kvm_host_cpu_state); +static inline void kvm_init_host_cpu_context(kvm_cpu_context_t *cpu_ctxt, + int cpu) +{ + /* The host's MPIDR is immutable, so let's set it up at boot time */ + cpu_ctxt->sys_regs[MPIDR_EL1] = cpu_logical_map(cpu); +} + void __kvm_enable_ssbs(void); static inline void __cpu_init_hyp_mode(phys_addr_t pgd_ptr, diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c index 68d6f7c3b237..2498f86defcb 100644 --- a/arch/arm64/kvm/hyp/sysreg-sr.c +++ b/arch/arm64/kvm/hyp/sysreg-sr.c @@ -52,7 +52,6 @@ static void __hyp_text __sysreg_save_user_state(struct kvm_cpu_context *ctxt) static void __hyp_text __sysreg_save_el1_state(struct kvm_cpu_context *ctxt) { - ctxt->sys_regs[MPIDR_EL1] = read_sysreg(vmpidr_el2); ctxt->sys_regs[CSSELR_EL1] = read_sysreg(csselr_el1); ctxt->sys_regs[SCTLR_EL1] = read_sysreg_el1(sctlr); ctxt->sys_regs[ACTLR_EL1] = read_sysreg(actlr_el1); |