On Thu, Mar 8, 2012 at 11:54 AM, Akshay Karle <akshay.a.karle@xxxxxxxxx> wrote: > From: Akshay Karle <akshay.a.karle@xxxxxxxxx> > Subject: [RFC 1/2] kvm: host-side changes for tmem on KVM > > Working at host: > Once the guest exits to the kvm host, the host determines that the guest exited > to perform some tmem operation(done at kvm_emulate_hypercall)and then > we use zcache to implement this required operations(performed by kvm_pv_tmem_op). > > --- > Diffstat for host patch: > arch/x86/include/asm/kvm_host.h | 1 > arch/x86/kvm/x86.c | 4 + > drivers/staging/zcache/zcache-main.c | 98 ++++++++++++++++++++++++++++++++--- > 3 files changed, 95 insertions(+), 8 deletions(-) > > diff -Napur vanilla/linux-3.1.5/arch/x86/include/asm/kvm_host.h linux-3.1.5//arch/x86/include/asm/kvm_host.h > --- vanilla/linux-3.1.5/arch/x86/include/asm/kvm_host.h 2011-12-09 22:27:05.000000000 +0530 > +++ linux-3.1.5//arch/x86/include/asm/kvm_host.h 2012-03-05 14:09:41.648006153 +0530 > @@ -668,6 +668,7 @@ int emulator_write_phys(struct kvm_vcpu > const void *val, int bytes); > int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes, > gpa_t addr, unsigned long *ret); > +int kvm_pv_tmem_op(struct kvm_vcpu *vcpu, gpa_t addr, unsigned long *ret); > u8 kvm_get_guest_memory_type(struct kvm_vcpu *vcpu, gfn_t gfn); > > extern bool tdp_enabled; > diff -Napur vanilla/linux-3.1.5/arch/x86/kvm/x86.c linux-3.1.5//arch/x86/kvm/x86.c > --- vanilla/linux-3.1.5/arch/x86/kvm/x86.c 2011-12-09 22:27:05.000000000 +0530 > +++ linux-3.1.5//arch/x86/kvm/x86.c 2012-03-05 14:09:41.652006083 +0530 > @@ -5267,6 +5267,10 @@ int kvm_emulate_hypercall(struct kvm_vcp > case KVM_HC_MMU_OP: > r = kvm_pv_mmu_op(vcpu, a0, hc_gpa(vcpu, a1, a2), &ret); > break; > + case KVM_HC_TMEM: > + r = kvm_pv_tmem_op(vcpu, a0, &ret); > + ret = ret - 1000; > + break; > default: > ret = -KVM_ENOSYS; > break; > diff -Napur vanilla/linux-3.1.5/drivers/staging/zcache/zcache-main.c linux-3.1.5//drivers/staging/zcache/zcache-main.c > --- vanilla/linux-3.1.5/drivers/staging/zcache/zcache-main.c 2011-12-09 22:27:05.000000000 +0530 > +++ linux-3.1.5//drivers/staging/zcache/zcache-main.c 2012-03-05 14:10:31.264006031 +0530 > @@ -30,6 +30,7 @@ > #include <linux/atomic.h> > #include <linux/math64.h> > #include "tmem.h" > +#include "kvm-tmem.h" This header should be introduced in this patch, not the next. > > #include "../zram/xvmalloc.h" /* if built in drivers/staging */ > > @@ -669,7 +670,6 @@ static struct zv_hdr *zv_create(struct x > int chunks = (alloc_size + (CHUNK_SIZE - 1)) >> CHUNK_SHIFT; > int ret; > > - BUG_ON(!irqs_disabled()); > BUG_ON(chunks >= NCHUNKS); > ret = xv_malloc(xvpool, alloc_size, > &page, &offset, ZCACHE_GFP_MASK); > @@ -1313,7 +1313,6 @@ static int zcache_compress(struct page * > unsigned char *wmem = __get_cpu_var(zcache_workmem); > char *from_va; > > - BUG_ON(!irqs_disabled()); > if (unlikely(dmem == NULL || wmem == NULL)) > goto out; /* no buffer, so can't compress */ > from_va = kmap_atomic(from, KM_USER0); > @@ -1533,7 +1532,6 @@ static int zcache_put_page(int cli_id, i > struct tmem_pool *pool; > int ret = -1; > > - BUG_ON(!irqs_disabled()); > pool = zcache_get_pool_by_id(cli_id, pool_id); > if (unlikely(pool == NULL)) > goto out; > @@ -1898,6 +1896,67 @@ struct frontswap_ops zcache_frontswap_re > #endif > > /* > + * tmem op to support tmem in kvm guests > + */ > + > +int kvm_pv_tmem_op(struct kvm_vcpu *vcpu, gpa_t addr, unsigned long *ret) > +{ > + struct tmem_ops op; > + struct tmem_oid oid; > + uint64_t pfn; > + struct page *page; > + int r; > + > + r = kvm_read_guest(vcpu->kvm, addr, &op, sizeof(op)); > + if (r < 0) > + return r; > + > + switch (op.cmd) { > + case TMEM_NEW_POOL: > + *ret = zcache_new_pool(op.u.new.cli_id, op.u.new.flags); > + break; > + case TMEM_DESTROY_POOL: > + *ret = zcache_destroy_pool(op.u.gen.cli_id, op.pool_id); > + break; > + case TMEM_NEW_PAGE: > + break; > + case TMEM_PUT_PAGE: > + pfn = gfn_to_pfn(vcpu->kvm, op.u.gen.pfn); > + page = pfn_to_page(pfn); > + oid.oid[0] = op.u.gen.oid[0]; > + oid.oid[1] = op.u.gen.oid[1]; > + oid.oid[2] = op.u.gen.oid[2]; > + VM_BUG_ON(!PageLocked(page)); > + *ret = zcache_put_page(op.u.gen.cli_id, op.pool_id, > + &oid, op.u.gen.index, page); > + break; > + case TMEM_GET_PAGE: > + pfn = gfn_to_pfn(vcpu->kvm, op.u.gen.pfn); > + page = pfn_to_page(pfn); > + oid.oid[0] = op.u.gen.oid[0]; > + oid.oid[1] = op.u.gen.oid[1]; > + oid.oid[2] = op.u.gen.oid[2]; > + *ret = zcache_get_page(TMEM_CLI, op.pool_id, > + &oid, op.u.gen.index, page); > + break; > + case TMEM_FLUSH_PAGE: > + oid.oid[0] = op.u.gen.oid[0]; > + oid.oid[1] = op.u.gen.oid[1]; > + oid.oid[2] = op.u.gen.oid[2]; > + *ret = zcache_flush_page(op.u.gen.cli_id, op.pool_id, > + &oid, op.u.gen.index); > + break; > + case TMEM_FLUSH_OBJECT: > + oid.oid[0] = op.u.gen.oid[0]; > + oid.oid[1] = op.u.gen.oid[1]; > + oid.oid[2] = op.u.gen.oid[2]; > + *ret = zcache_flush_object(op.u.gen.cli_id, op.pool_id, &oid); > + break; > + } > + return 0; > +} > + > +/* > * zcache initialization > * NOTE FOR NOW zcache MUST BE PROVIDED AS A KERNEL BOOT PARAMETER OR > * NOTHING HAPPENS! > @@ -1934,10 +1993,19 @@ static int __init no_frontswap(char *s) > > __setup("nofrontswap", no_frontswap); > > +static int kvm_tmem_enabled = 0; > + > +static int __init enable_kvm_tmem(char *s) > +{ > + kvm_tmem_enabled = 1; > + return 1; > +} > + > +__setup("kvmtmem", enable_kvm_tmem); > + > static int __init zcache_init(void) > { > int ret = 0; > - > #ifdef CONFIG_SYSFS > ret = sysfs_create_group(mm_kobj, &zcache_attr_group); > if (ret) { > @@ -1946,7 +2014,7 @@ static int __init zcache_init(void) > } > #endif /* CONFIG_SYSFS */ > #if defined(CONFIG_CLEANCACHE) || defined(CONFIG_FRONTSWAP) > - if (zcache_enabled) { > + if (zcache_enabled || kvm_tmem_enabled) { > unsigned int cpu; > > tmem_register_hostops(&zcache_hostops); > @@ -1966,11 +2034,25 @@ static int __init zcache_init(void) > sizeof(struct tmem_objnode), 0, 0, NULL); > zcache_obj_cache = kmem_cache_create("zcache_obj", > sizeof(struct tmem_obj), 0, 0, NULL); > - ret = zcache_new_client(LOCAL_CLIENT); > - if (ret) { > - pr_err("zcache: can't create client\n"); > + if(kvm_tmem_enabled) { > + ret = zcache_new_client(TMEM_CLI); > + if(ret) { > + pr_err("zcache: can't create client\n"); > + goto out; > + } > + zbud_init(); > + register_shrinker(&zcache_shrinker); > + pr_info("zcache: transcendent memory enabled using kernel " > + "for kvm guests\n"); > goto out; > } > + else { > + ret = zcache_new_client(LOCAL_CLIENT); > + if (ret) { > + pr_err("zcache: can't create client\n"); > + goto out; > + } > + } > #endif > #ifdef CONFIG_CLEANCACHE > if (zcache_enabled && use_cleancache) { > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html