[PATCH v3 01/19] arm/arm64: KVM: rework MPIDR assignment and add accessors
Christoffer Dall
christoffer.dall at linaro.org
Mon Nov 3 05:13:22 PST 2014
On Fri, Oct 31, 2014 at 05:26:36PM +0000, Andre Przywara wrote:
> The virtual MPIDR registers (containing topology information) for the
> guest are currently mapped linearily to the vcpu_id. Improve this
> mapping for arm64 by using three levels to not artificially limit the
> number of vCPUs. Also add an accessor to later allow easier access to
> a vCPU with a given MPIDR.
> Use this new accessor in the PSCI emulation.
>
> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
> ---
> arch/arm/include/asm/kvm_emulate.h | 3 ++-
> arch/arm/include/asm/kvm_host.h | 2 ++
> arch/arm/kvm/arm.c | 15 +++++++++++++++
> arch/arm/kvm/psci.c | 15 ++++-----------
> arch/arm64/include/asm/kvm_emulate.h | 3 ++-
> arch/arm64/include/asm/kvm_host.h | 2 ++
> arch/arm64/kvm/sys_regs.c | 11 +++++++++--
> 7 files changed, 36 insertions(+), 15 deletions(-)
>
> diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h
> index b9db269..bd54383 100644
> --- a/arch/arm/include/asm/kvm_emulate.h
> +++ b/arch/arm/include/asm/kvm_emulate.h
> @@ -23,6 +23,7 @@
> #include <asm/kvm_asm.h>
> #include <asm/kvm_mmio.h>
> #include <asm/kvm_arm.h>
> +#include <asm/cputype.h>
>
> unsigned long *vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num);
> unsigned long *vcpu_spsr(struct kvm_vcpu *vcpu);
> @@ -164,7 +165,7 @@ static inline u32 kvm_vcpu_hvc_get_imm(struct kvm_vcpu *vcpu)
>
> static inline unsigned long kvm_vcpu_get_mpidr(struct kvm_vcpu *vcpu)
> {
> - return vcpu->arch.cp15[c0_MPIDR];
> + return vcpu->arch.cp15[c0_MPIDR] & MPIDR_HWID_BITMASK;
> }
continuing the discussion from the previous version, yes, please don't
call it get_mpidr() if it returns a masked off version of get_mpidr(),
then call it get_mpidr_hwid() or something.
>
> static inline void kvm_vcpu_set_be(struct kvm_vcpu *vcpu)
> diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
> index 53036e2..b443dfe 100644
> --- a/arch/arm/include/asm/kvm_host.h
> +++ b/arch/arm/include/asm/kvm_host.h
> @@ -236,6 +236,8 @@ static inline void vgic_arch_setup(const struct vgic_params *vgic)
> int kvm_perf_init(void);
> int kvm_perf_teardown(void);
>
> +struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr);
> +
> static inline void kvm_arch_hardware_disable(void) {}
> static inline void kvm_arch_hardware_unsetup(void) {}
> static inline void kvm_arch_sync_events(struct kvm *kvm) {}
> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
> index 9e193c8..61f13cc 100644
> --- a/arch/arm/kvm/arm.c
> +++ b/arch/arm/kvm/arm.c
> @@ -977,6 +977,21 @@ static void check_kvm_target_cpu(void *ret)
> *(int *)ret = kvm_target_cpu();
> }
>
> +struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr)
> +{
> + unsigned long c_mpidr;
> + struct kvm_vcpu *vcpu;
> + int i;
> +
> + mpidr &= MPIDR_HWID_BITMASK;
> + kvm_for_each_vcpu(i, vcpu, kvm) {
> + c_mpidr = kvm_vcpu_get_mpidr(vcpu);
> + if (c_mpidr == mpidr)
> + return vcpu;
why do you need the c_mpidr variable at all?
> + }
> + return NULL;
> +}
> +
> /**
> * Initialize Hyp-mode and memory mappings on all CPUs.
> */
> diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c
> index 09cf377..49f0992 100644
> --- a/arch/arm/kvm/psci.c
> +++ b/arch/arm/kvm/psci.c
> @@ -21,6 +21,7 @@
> #include <asm/cputype.h>
> #include <asm/kvm_emulate.h>
> #include <asm/kvm_psci.h>
> +#include <asm/kvm_host.h>
>
> /*
> * This is an implementation of the Power State Coordination Interface
> @@ -65,25 +66,17 @@ static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu)
> static unsigned long kvm_psci_vcpu_on(struct kvm_vcpu *source_vcpu)
> {
> struct kvm *kvm = source_vcpu->kvm;
> - struct kvm_vcpu *vcpu = NULL, *tmp;
> + struct kvm_vcpu *vcpu = NULL;
> wait_queue_head_t *wq;
> unsigned long cpu_id;
> unsigned long context_id;
> - unsigned long mpidr;
> phys_addr_t target_pc;
> - int i;
>
> - cpu_id = *vcpu_reg(source_vcpu, 1);
> + cpu_id = *vcpu_reg(source_vcpu, 1) & MPIDR_HWID_BITMASK;
> if (vcpu_mode_is_32bit(source_vcpu))
> cpu_id &= ~((u32) 0);
>
> - kvm_for_each_vcpu(i, tmp, kvm) {
> - mpidr = kvm_vcpu_get_mpidr(tmp);
> - if ((mpidr & MPIDR_HWID_BITMASK) == (cpu_id & MPIDR_HWID_BITMASK)) {
> - vcpu = tmp;
> - break;
> - }
> - }
> + vcpu = kvm_mpidr_to_vcpu(kvm, cpu_id);
>
> /*
> * Make sure the caller requested a valid CPU and that the CPU is
> diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
> index 5674a55..37316dd 100644
> --- a/arch/arm64/include/asm/kvm_emulate.h
> +++ b/arch/arm64/include/asm/kvm_emulate.h
> @@ -27,6 +27,7 @@
> #include <asm/kvm_arm.h>
> #include <asm/kvm_mmio.h>
> #include <asm/ptrace.h>
> +#include <asm/cputype.h>
>
> unsigned long *vcpu_reg32(const struct kvm_vcpu *vcpu, u8 reg_num);
> unsigned long *vcpu_spsr32(const struct kvm_vcpu *vcpu);
> @@ -184,7 +185,7 @@ static inline u8 kvm_vcpu_trap_get_fault_type(const struct kvm_vcpu *vcpu)
>
> static inline unsigned long kvm_vcpu_get_mpidr(struct kvm_vcpu *vcpu)
> {
> - return vcpu_sys_reg(vcpu, MPIDR_EL1);
> + return vcpu_sys_reg(vcpu, MPIDR_EL1) & MPIDR_HWID_BITMASK;
> }
>
> static inline void kvm_vcpu_set_be(struct kvm_vcpu *vcpu)
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index 2012c4b..286bb61 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -207,6 +207,8 @@ int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
> int kvm_perf_init(void);
> int kvm_perf_teardown(void);
>
> +struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr);
> +
> static inline void __cpu_init_hyp_mode(phys_addr_t boot_pgd_ptr,
> phys_addr_t pgd_ptr,
> unsigned long hyp_stack_ptr,
> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
> index 4cc3b71..dcc5867 100644
> --- a/arch/arm64/kvm/sys_regs.c
> +++ b/arch/arm64/kvm/sys_regs.c
> @@ -252,10 +252,17 @@ static void reset_amair_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
>
> static void reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
> {
> + u64 mpidr;
> +
> /*
> - * Simply map the vcpu_id into the Aff0 field of the MPIDR.
> + * Map the vcpu_id into the first three Aff fields of the MPIDR.
> + * Aff0 uses only 16 CPUs, since there is a SGI injection
> + * limitation of GICv3.
This last sentence is worded weirdly, so I suggested an alternative
version in my last review, which you missed/ignored. Please address it.
Thanks,
-Christoffer
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