Re: [PATCH v2] kvm/book3s: Make kernel emulated H_PUT_TCE available for "PR" KVM

[Alexander Graf <agraf@suse.de>]

On 03/16/2012 08:58 AM, Benjamin Herrenschmidt wrote:
> There is nothing in the code for emulating TCE tables in the kernel
> that prevents it from working on "PR" KVM... other than ifdef's and
> location of the code.
>
> This renames book3s_64_vio_hv.c to book3s_64_vio.c and moves the
> bulk of the code there.
>
> This speeds things up a bit on my G5.
> ---
>
> v2. Changed the ifdef as per discussion with Alex. I still didn't
> manage to get git to figure out the rename but that's no big deal,
> the old file had only one small function in it. There's no code
> change, you can trust me on that one, It's really just moving
> things around :-)
>
>   arch/powerpc/include/asm/kvm_host.h |    4 +-
>   arch/powerpc/include/asm/kvm_ppc.h  |    2 +
>   arch/powerpc/kvm/Makefile           |    3 +-
>   arch/powerpc/kvm/book3s_64_vio.c    |  187 +++++++++++++++++++++++++++++++++++
>   arch/powerpc/kvm/book3s_64_vio_hv.c |   73 --------------
>   arch/powerpc/kvm/book3s_hv.c        |  109 --------------------
>   arch/powerpc/kvm/book3s_pr.c        |    3 +
>   arch/powerpc/kvm/book3s_pr_papr.c   |   18 ++++
>   arch/powerpc/kvm/powerpc.c          |    8 +-
>   9 files changed, 221 insertions(+), 186 deletions(-)
>   create mode 100644 arch/powerpc/kvm/book3s_64_vio.c
>   delete mode 100644 arch/powerpc/kvm/book3s_64_vio_hv.c
>
> diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
> index 42a527e..d848cdc 100644
> --- a/arch/powerpc/include/asm/kvm_host.h
> +++ b/arch/powerpc/include/asm/kvm_host.h
> @@ -237,7 +237,6 @@ struct kvm_arch {
>   	unsigned long vrma_slb_v;
>   	int rma_setup_done;
>   	int using_mmu_notifiers;
> -	struct list_head spapr_tce_tables;
>   	spinlock_t slot_phys_lock;
>   	unsigned long *slot_phys[KVM_MEM_SLOTS_NUM];
>   	int slot_npages[KVM_MEM_SLOTS_NUM];
> @@ -245,6 +244,9 @@ struct kvm_arch {
>   	struct kvmppc_vcore *vcores[KVM_MAX_VCORES];
>   	struct kvmppc_linear_info *hpt_li;
>   #endif /* CONFIG_KVM_BOOK3S_64_HV */
> +#ifdef CONFIG_PPC_BOOK3S_64
> +	struct list_head spapr_tce_tables;
> +#endif
>   };
>
>   /*
> diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
> index 7f0a3da..c1069f6 100644
> --- a/arch/powerpc/include/asm/kvm_ppc.h
> +++ b/arch/powerpc/include/asm/kvm_ppc.h
> @@ -126,6 +126,8 @@ extern void kvmppc_map_vrma(struct kvm_vcpu *vcpu,
>   extern int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu);
>   extern long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
>   				struct kvm_create_spapr_tce *args);
> +extern long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
> +			     unsigned long ioba, unsigned long tce);
>   extern long kvm_vm_ioctl_allocate_rma(struct kvm *kvm,
>   				struct kvm_allocate_rma *rma);
>   extern struct kvmppc_linear_info *kvm_alloc_rma(void);
> diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
> index 25225ae..8c95def 100644
> --- a/arch/powerpc/kvm/Makefile
> +++ b/arch/powerpc/kvm/Makefile
> @@ -54,6 +54,7 @@ kvm-book3s_64-objs-$(CONFIG_KVM_BOOK3S_64_PR) := \
>   	book3s_paired_singles.o \
>   	book3s_pr.o \
>   	book3s_pr_papr.o \
> +	book3s_64_vio.o \
>   	book3s_emulate.o \
>   	book3s_interrupts.o \
>   	book3s_mmu_hpte.o \
> @@ -70,7 +71,7 @@ kvm-book3s_64-objs-$(CONFIG_KVM_BOOK3S_64_HV) := \
>   kvm-book3s_64-builtin-objs-$(CONFIG_KVM_BOOK3S_64_HV) := \
>   	book3s_hv_rmhandlers.o \
>   	book3s_hv_rm_mmu.o \
> -	book3s_64_vio_hv.o \
> +	book3s_64_vio.o \
>   	book3s_hv_builtin.o
>
>   kvm-book3s_64-module-objs := \
> diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c
> new file mode 100644
> index 0000000..193ba68
> --- /dev/null
> +++ b/arch/powerpc/kvm/book3s_64_vio.c
> @@ -0,0 +1,187 @@
> +/*
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License, version 2, as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
> + *
> + * Copyright 2010 Paul Mackerras, IBM Corp.<paulus@au1.ibm.com>
> + * Copyright 2011 David Gibson, IBM Corporation<dwg@au1.ibm.com>
> + */
> +
> +#include<linux/types.h>
> +#include<linux/string.h>
> +#include<linux/kvm.h>
> +#include<linux/kvm_host.h>
> +#include<linux/highmem.h>
> +#include<linux/gfp.h>
> +#include<linux/slab.h>
> +#include<linux/hugetlb.h>
> +#include<linux/list.h>
> +#include<linux/anon_inodes.h>
> +
> +#include<asm/tlbflush.h>
> +#include<asm/kvm_ppc.h>
> +#include<asm/kvm_book3s.h>
> +#include<asm/mmu-hash64.h>
> +#include<asm/hvcall.h>
> +#include<asm/synch.h>
> +#include<asm/ppc-opcode.h>
> +#include<asm/kvm_host.h>
> +#include<asm/udbg.h>
> +
> +#define TCES_PER_PAGE	(PAGE_SIZE / sizeof(u64))
> +
> +/* WARNING: This will be called in real-mode on HV KVM and virtual
> + *          mode on PR KVM
> + */
> +long kvmppc_h_put_tce(struct kvm_vcpu *vcpu, unsigned long liobn,
> +		      unsigned long ioba, unsigned long tce)
> +{
> +	struct kvm *kvm = vcpu->kvm;
> +	struct kvmppc_spapr_tce_table *stt;
> +
> +	/* udbg_printf("H_PUT_TCE(): liobn=0x%lx ioba=0x%lx, tce=0x%lx\n", */
> +	/* 	    liobn, ioba, tce); */
> +
> +	list_for_each_entry(stt,&kvm->arch.spapr_tce_tables, list) {
> +		if (stt->liobn == liobn) {
> +			unsigned long idx = ioba>>  SPAPR_TCE_SHIFT;
> +			struct page *page;
> +			u64 *tbl;
> +
> +			/* udbg_printf("H_PUT_TCE: liobn 0x%lx =>  stt=%p  window_size=0x%x\n", */
> +			/* 	    liobn, stt, stt->window_size); */
> +			if (ioba>= stt->window_size)
> +				return H_PARAMETER;
> +
> +			page = stt->pages[idx / TCES_PER_PAGE];
> +			tbl = (u64 *)page_address(page);
> +
> +			/* FIXME: Need to validate the TCE itself */
> +			/* udbg_printf("tce @ %p\n",&tbl[idx % TCES_PER_PAGE]); */
> +			tbl[idx % TCES_PER_PAGE] = tce;
> +			return H_SUCCESS;
> +		}
> +	}
> +
> +	/* Didn't find the liobn, punt it to userspace */
> +	return H_TOO_HARD;
> +}

This function needs to be available in real mode on HV, but the ones 
below must be on module code when kvm is compiled as a module, because 
they call kvm infrastructure which lives in module code.


Alex