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Commit dc83b8bc authored by Scott Wood's avatar Scott Wood Committed by Avi Kivity
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KVM: PPC: e500: MMU API 



This implements a shared-memory API for giving host userspace access to
the guest's TLB.

Signed-off-by: default avatarScott Wood <scottwood@freescale.com>
Signed-off-by: default avatarAlexander Graf <agraf@suse.de>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 0164c0f0

Documentation/virtual/kvm/api.txt

+74 −0
Original line number Diff line number Diff line
@@ -1409,6 +1409,38 @@ The following flags are defined: 
If datamatch flag is set, the event will be signaled only if the written value

to the registered address is equal to datamatch in struct kvm_ioeventfd.



4.59 KVM_DIRTY_TLB



Capability: KVM_CAP_SW_TLB

Architectures: ppc

Type: vcpu ioctl

Parameters: struct kvm_dirty_tlb (in)

Returns: 0 on success, -1 on error



struct kvm_dirty_tlb {

	__u64 bitmap;

	__u32 num_dirty;

};



This must be called whenever userspace has changed an entry in the shared

TLB, prior to calling KVM_RUN on the associated vcpu.



The "bitmap" field is the userspace address of an array.  This array

consists of a number of bits, equal to the total number of TLB entries as

determined by the last successful call to KVM_CONFIG_TLB, rounded up to the

nearest multiple of 64.



Each bit corresponds to one TLB entry, ordered the same as in the shared TLB

array.



The array is little-endian: the bit 0 is the least significant bit of the

first byte, bit 8 is the least significant bit of the second byte, etc.

This avoids any complications with differing word sizes.



The "num_dirty" field is a performance hint for KVM to determine whether it

should skip processing the bitmap and just invalidate everything.  It must

be set to the number of set bits in the bitmap.



4.62 KVM_CREATE_SPAPR_TCE



Capability: KVM_CAP_SPAPR_TCE
@@ -1842,3 +1874,45 @@ HTAB address part of SDR1 contains an HVA instead of a GPA, as PAPR keeps the 
HTAB invisible to the guest.



When this capability is enabled, KVM_EXIT_PAPR_HCALL can occur.



6.3 KVM_CAP_SW_TLB



Architectures: ppc

Parameters: args[0] is the address of a struct kvm_config_tlb

Returns: 0 on success; -1 on error



struct kvm_config_tlb {

	__u64 params;

	__u64 array;

	__u32 mmu_type;

	__u32 array_len;

};



Configures the virtual CPU's TLB array, establishing a shared memory area

between userspace and KVM.  The "params" and "array" fields are userspace

addresses of mmu-type-specific data structures.  The "array_len" field is an

safety mechanism, and should be set to the size in bytes of the memory that

userspace has reserved for the array.  It must be at least the size dictated

by "mmu_type" and "params".



While KVM_RUN is active, the shared region is under control of KVM.  Its

contents are undefined, and any modification by userspace results in

boundedly undefined behavior.



On return from KVM_RUN, the shared region will reflect the current state of

the guest's TLB.  If userspace makes any changes, it must call KVM_DIRTY_TLB

to tell KVM which entries have been changed, prior to calling KVM_RUN again

on this vcpu.



For mmu types KVM_MMU_FSL_BOOKE_NOHV and KVM_MMU_FSL_BOOKE_HV:

 - The "params" field is of type "struct kvm_book3e_206_tlb_params".

 - The "array" field points to an array of type "struct

   kvm_book3e_206_tlb_entry".

 - The array consists of all entries in the first TLB, followed by all

   entries in the second TLB.

 - Within a TLB, entries are ordered first by increasing set number.  Within a

   set, entries are ordered by way (increasing ESEL).

 - The hash for determining set number in TLB0 is: (MAS2 >> 12) & (num_sets - 1)

   where "num_sets" is the tlb_sizes[] value divided by the tlb_ways[] value.

 - The tsize field of mas1 shall be set to 4K on TLB0, even though the

   hardware ignores this value for TLB0.

arch/powerpc/include/asm/kvm.h

+35 −0
Original line number Diff line number Diff line
@@ -296,4 +296,39 @@ struct kvm_allocate_rma { 
	__u64 rma_size;

};



struct kvm_book3e_206_tlb_entry {

	__u32 mas8;

	__u32 mas1;

	__u64 mas2;

	__u64 mas7_3;

};



struct kvm_book3e_206_tlb_params {

	/*

	 * For mmu types KVM_MMU_FSL_BOOKE_NOHV and KVM_MMU_FSL_BOOKE_HV:

	 *

	 * - The number of ways of TLB0 must be a power of two between 2 and

	 *   16.

	 * - TLB1 must be fully associative.

	 * - The size of TLB0 must be a multiple of the number of ways, and

	 *   the number of sets must be a power of two.

	 * - The size of TLB1 may not exceed 64 entries.

	 * - TLB0 supports 4 KiB pages.

	 * - The page sizes supported by TLB1 are as indicated by

	 *   TLB1CFG (if MMUCFG[MAVN] = 0) or TLB1PS (if MMUCFG[MAVN] = 1)

	 *   as returned by KVM_GET_SREGS.

	 * - TLB2 and TLB3 are reserved, and their entries in tlb_sizes[]

	 *   and tlb_ways[] must be zero.

	 *

	 * tlb_ways[n] = tlb_sizes[n] means the array is fully associative.

	 *

	 * KVM will adjust TLBnCFG based on the sizes configured here,

	 * though arrays greater than 2048 entries will have TLBnCFG[NENTRY]

	 * set to zero.

	 */

	__u32 tlb_sizes[4];

	__u32 tlb_ways[4];

	__u32 reserved[8];

};



#endif /* __LINUX_KVM_POWERPC_H */

arch/powerpc/include/asm/kvm_e500.h

+11 −13
Original line number Diff line number Diff line
@@ -22,13 +22,6 @@ 
#define E500_PID_NUM   3

#define E500_TLB_NUM   2



struct tlbe{

	u32 mas1;

	u32 mas2;

	u32 mas3;

	u32 mas7;

};



#define E500_TLB_VALID 1

#define E500_TLB_DIRTY 2
@@ -48,13 +41,17 @@ struct kvmppc_e500_tlb_params { 
};



struct kvmppc_vcpu_e500 {

	/* Unmodified copy of the guest's TLB. */

	struct tlbe *gtlb_arch[E500_TLB_NUM];

	/* Unmodified copy of the guest's TLB -- shared with host userspace. */

	struct kvm_book3e_206_tlb_entry *gtlb_arch;



	/* Starting entry number in gtlb_arch[] */

	int gtlb_offset[E500_TLB_NUM];



	/* KVM internal information associated with each guest TLB entry */

	struct tlbe_priv *gtlb_priv[E500_TLB_NUM];



	unsigned int gtlb_size[E500_TLB_NUM];

	struct kvmppc_e500_tlb_params gtlb_params[E500_TLB_NUM];



	unsigned int gtlb_nv[E500_TLB_NUM];



	/*
@@ -68,7 +65,6 @@ struct kvmppc_vcpu_e500 { 
	 * and back, and our host TLB entries got evicted).

	 */

	struct tlbe_ref *tlb_refs[E500_TLB_NUM];



	unsigned int host_tlb1_nv;



	u32 host_pid[E500_PID_NUM];
@@ -78,11 +74,10 @@ struct kvmppc_vcpu_e500 { 
	u32 mas0;

	u32 mas1;

	u32 mas2;

	u32 mas3;

	u64 mas7_3;

	u32 mas4;

	u32 mas5;

	u32 mas6;

	u32 mas7;



	/* vcpu id table */

	struct vcpu_id_table *idt;
@@ -95,6 +90,9 @@ struct kvmppc_vcpu_e500 { 
	u32 tlb1cfg;

	u64 mcar;



	struct page **shared_tlb_pages;

	int num_shared_tlb_pages;



	struct kvm_vcpu vcpu;

};

arch/powerpc/include/asm/kvm_ppc.h

+5 −0
Original line number Diff line number Diff line
@@ -193,4 +193,9 @@ static inline void kvm_rma_init(void) 
{}

#endif



int kvm_vcpu_ioctl_config_tlb(struct kvm_vcpu *vcpu,

			      struct kvm_config_tlb *cfg);

int kvm_vcpu_ioctl_dirty_tlb(struct kvm_vcpu *vcpu,

			     struct kvm_dirty_tlb *cfg);



#endif /* __POWERPC_KVM_PPC_H__ */

arch/powerpc/kvm/e500.c

+2 −3
Original line number Diff line number Diff line
@@ -121,7 +121,7 @@ void kvmppc_core_get_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs) 
	sregs->u.e.mas0 = vcpu_e500->mas0;

	sregs->u.e.mas1 = vcpu_e500->mas1;

	sregs->u.e.mas2 = vcpu_e500->mas2;

	sregs->u.e.mas7_3 = ((u64)vcpu_e500->mas7 << 32) | vcpu_e500->mas3;

	sregs->u.e.mas7_3 = vcpu_e500->mas7_3;

	sregs->u.e.mas4 = vcpu_e500->mas4;

	sregs->u.e.mas6 = vcpu_e500->mas6;
@@ -154,8 +154,7 @@ int kvmppc_core_set_sregs(struct kvm_vcpu *vcpu, struct kvm_sregs *sregs) 
		vcpu_e500->mas0 = sregs->u.e.mas0;

		vcpu_e500->mas1 = sregs->u.e.mas1;

		vcpu_e500->mas2 = sregs->u.e.mas2;

		vcpu_e500->mas7 = sregs->u.e.mas7_3 >> 32;

		vcpu_e500->mas3 = (u32)sregs->u.e.mas7_3;

		vcpu_e500->mas7_3 = sregs->u.e.mas7_3;

		vcpu_e500->mas4 = sregs->u.e.mas4;

		vcpu_e500->mas6 = sregs->u.e.mas6;

	}