[RFC PATCH 04/16] KVM: PPC: factor out lpid allocator from book3s_64_mmu_hv

[Alexander Graf]

On 21.12.2011, at 02:34, Scott Wood wrote:

> We'll use it on e500mc as well.
> 
> Signed-off-by: Scott Wood <scottwood at freescale.com>
> ---
> arch/powerpc/include/asm/kvm_book3s.h |    3 ++
> arch/powerpc/include/asm/kvm_booke.h  |    3 ++
> arch/powerpc/include/asm/kvm_ppc.h    |    5 ++++
> arch/powerpc/kvm/book3s_64_mmu_hv.c   |   26 +++++++++---------------
> arch/powerpc/kvm/powerpc.c            |   34 +++++++++++++++++++++++++++++++++
> 5 files changed, 55 insertions(+), 16 deletions(-)
> 
> diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
> index 60e069e..58c8bec 100644
> --- a/arch/powerpc/include/asm/kvm_book3s.h
> +++ b/arch/powerpc/include/asm/kvm_book3s.h
> @@ -448,4 +448,7 @@ static inline bool kvmppc_critical_section(struct kvm_vcpu *vcpu)
> 
> #define INS_DCBZ			0x7c0007ec
> 
> +/* LPIDs we support with this build -- runtime limit may be lower */
> +#define KVMPPC_NR_LPIDS			(LPID_RSVD + 1)
> +
> #endif /* __ASM_KVM_BOOK3S_H__ */
> diff --git a/arch/powerpc/include/asm/kvm_booke.h b/arch/powerpc/include/asm/kvm_booke.h
> index e20c162..138118e 100644
> --- a/arch/powerpc/include/asm/kvm_booke.h
> +++ b/arch/powerpc/include/asm/kvm_booke.h
> @@ -23,6 +23,9 @@
> #include <linux/types.h>
> #include <linux/kvm_host.h>
> 
> +/* LPIDs we support with this build -- runtime limit may be lower */
> +#define KVMPPC_NR_LPIDS                        64
> +
> static inline void kvmppc_set_gpr(struct kvm_vcpu *vcpu, int num, ulong val)
> {
> 	vcpu->arch.regs.gpr[num] = val;
> diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
> index a61b5b5..5524f88 100644
> --- a/arch/powerpc/include/asm/kvm_ppc.h
> +++ b/arch/powerpc/include/asm/kvm_ppc.h
> @@ -202,4 +202,9 @@ int kvm_vcpu_ioctl_config_tlb(struct kvm_vcpu *vcpu,
> int kvm_vcpu_ioctl_dirty_tlb(struct kvm_vcpu *vcpu,
> 			     struct kvm_dirty_tlb *cfg);
> 
> +long kvmppc_alloc_lpid(void);
> +void kvmppc_claim_lpid(long lpid);
> +void kvmppc_free_lpid(long lpid);
> +void kvmppc_init_lpid(unsigned long nr_lpids);
> +
> #endif /* __POWERPC_KVM_PPC_H__ */
> diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
> index 66d6452..45b6f0e 100644
> --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
> +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
> @@ -36,13 +36,11 @@
> 
> /* POWER7 has 10-bit LPIDs, PPC970 has 6-bit LPIDs */
> #define MAX_LPID_970	63
> -#define NR_LPIDS	(LPID_RSVD + 1)
> -unsigned long lpid_inuse[BITS_TO_LONGS(NR_LPIDS)];
> 
> long kvmppc_alloc_hpt(struct kvm *kvm)
> {
> 	unsigned long hpt;
> -	unsigned long lpid;
> +	long lpid;
> 	struct revmap_entry *rev;
> 
> 	/* Allocate guest's hashed page table */
> @@ -62,14 +60,9 @@ long kvmppc_alloc_hpt(struct kvm *kvm)
> 	}
> 	kvm->arch.revmap = rev;
> 
> -	/* Allocate the guest's logical partition ID */
> -	do {
> -		lpid = find_first_zero_bit(lpid_inuse, NR_LPIDS);
> -		if (lpid >= NR_LPIDS) {
> -			pr_err("kvm_alloc_hpt: No LPIDs free\n");
> -			goto out_freeboth;
> -		}
> -	} while (test_and_set_bit(lpid, lpid_inuse));
> +	lpid = kvmppc_alloc_lpid();
> +	if (lpid < 0)
> +		goto out_freeboth;
> 
> 	kvm->arch.sdr1 = __pa(hpt) | (HPT_ORDER - 18);
> 	kvm->arch.lpid = lpid;
> @@ -86,7 +79,7 @@ long kvmppc_alloc_hpt(struct kvm *kvm)
> 
> void kvmppc_free_hpt(struct kvm *kvm)
> {
> -	clear_bit(kvm->arch.lpid, lpid_inuse);
> +	kvmppc_free_lpid(kvm->arch.lpid);
> 	vfree(kvm->arch.revmap);
> 	free_pages(kvm->arch.hpt_virt, HPT_ORDER - PAGE_SHIFT);
> }
> @@ -158,8 +151,7 @@ int kvmppc_mmu_hv_init(void)
> 	if (!cpu_has_feature(CPU_FTR_HVMODE))
> 		return -EINVAL;
> 
> -	memset(lpid_inuse, 0, sizeof(lpid_inuse));
> -
> +	/* POWER7 has 10-bit LPIDs, PPC970 and e500mc have 6-bit LPIDs */
> 	if (cpu_has_feature(CPU_FTR_ARCH_206)) {
> 		host_lpid = mfspr(SPRN_LPID);	/* POWER7 */
> 		rsvd_lpid = LPID_RSVD;
> @@ -168,9 +160,11 @@ int kvmppc_mmu_hv_init(void)
> 		rsvd_lpid = MAX_LPID_970;
> 	}
> 
> -	set_bit(host_lpid, lpid_inuse);
> +	kvmppc_init_lpid(rsvd_lpid + 1);
> +
> +	kvmppc_claim_lpid(host_lpid);
> 	/* rsvd_lpid is reserved for use in partition switching */
> -	set_bit(rsvd_lpid, lpid_inuse);
> +	kvmppc_claim_lpid(rsvd_lpid);
> 
> 	return 0;
> }
> diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
> index 64c738dc..42701e5 100644
> --- a/arch/powerpc/kvm/powerpc.c
> +++ b/arch/powerpc/kvm/powerpc.c

Paul, does this work for you? IIRC you need this code to be available from real mode, which powerpc.c isn't in, right?


Alex

> @@ -800,6 +800,40 @@ out:
> 	return r;
> }
> 
> +static unsigned long lpid_inuse[BITS_TO_LONGS(KVMPPC_NR_LPIDS)];
> +static unsigned long nr_lpids;
> +
> +long kvmppc_alloc_lpid(void)
> +{
> +	long lpid;
> +
> +	do {
> +		lpid = find_first_zero_bit(lpid_inuse, KVMPPC_NR_LPIDS);
> +		if (lpid >= nr_lpids) {
> +			pr_err("%s: No LPIDs free\n", __func__);
> +			return -ENOMEM;
> +		}
> +	} while (test_and_set_bit(lpid, lpid_inuse));
> +
> +	return lpid;
> +}
> +
> +void kvmppc_claim_lpid(long lpid)
> +{
> +	set_bit(lpid, lpid_inuse);
> +}
> +
> +void kvmppc_free_lpid(long lpid)
> +{
> +	clear_bit(lpid, lpid_inuse);
> +}
> +
> +void kvmppc_init_lpid(unsigned long nr_lpids_param)
> +{
> +	nr_lpids = min_t(unsigned long, KVMPPC_NR_LPIDS, nr_lpids_param);
> +	memset(lpid_inuse, 0, sizeof(lpid_inuse));
> +}
> +
> int kvm_arch_init(void *opaque)
> {
> 	return 0;
> -- 
> 1.7.7.rc3.4.g8d714
> 
>