Hi,
I think I got mmiotracing back to work on my machine.
Would you please test this patch on your machines too? I still got some UNKNOWN
entries in the mmiotrace file, but besides that it seems to work.
I have no idea if that's the right way though, and it needs a big cleanup,
but I
just wanted to see if the basic idea works
the patch should apply just fine on any 4.4 kernel
happy testing
---
diff -ur linux-4.4.0-gentoo/arch/x86/mm/kmmio.c linux/arch/x86/mm/kmmio.c
--- linux-4.4.0-gentoo/arch/x86/mm/kmmio.c 2016-01-11 00:01:32.000000000 +0100
+++ linux/arch/x86/mm/kmmio.c 2016-02-09 23:11:19.466095771 +0100
@@ -33,7 +33,7 @@
struct kmmio_fault_page {
struct list_head list;
struct kmmio_fault_page *release_next;
- unsigned long page; /* location of the fault page */
+ unsigned long addr; /* the requested address */
pteval_t old_presence; /* page presence prior to arming */
bool armed;
@@ -70,9 +70,27 @@
static struct list_head kmmio_page_table[KMMIO_PAGE_TABLE_SIZE];
static LIST_HEAD(kmmio_probes);
-static struct list_head *kmmio_page_list(unsigned long page)
+static struct list_head *kmmio_page_list(unsigned long addr)
{
- return &kmmio_page_table[hash_long(page, KMMIO_PAGE_HASH_BITS)];
+ unsigned int l;
+ pte_t *pte = lookup_address(addr, &l);
+ if (!pte)
+ return NULL;
+
+ switch (l) {
+ case PG_LEVEL_4K:
+ addr &= (~(u64)(0x0)) << 12;
+ break;
+ case PG_LEVEL_2M:
+ addr &= (~(u64)(0x0)) << 21;
+ break;
+ case PG_LEVEL_1G:
+ addr &= (~(u64)(0x0)) << 30;
+ break;
+ default:
+ return NULL;
+ }
+ return &kmmio_page_table[hash_long(addr, KMMIO_PAGE_HASH_BITS)];
}
/* Accessed per-cpu */
@@ -98,15 +116,33 @@
}
/* You must be holding RCU read lock. */
-static struct kmmio_fault_page *get_kmmio_fault_page(unsigned long page)
+static struct kmmio_fault_page *get_kmmio_fault_page(unsigned long addr)
{
struct list_head *head;
struct kmmio_fault_page *f;
+ unsigned int l;
+ pte_t *pte = lookup_address(addr, &l);
+
+ if (!pte)
+ return NULL;
- page &= PAGE_MASK;
- head = kmmio_page_list(page);
+ switch (l) {
+ case PG_LEVEL_4K:
+ addr &= (~(u64)(0x0)) << 12;
+ break;
+ case PG_LEVEL_2M:
+ addr &= (~(u64)(0x0)) << 21;
+ break;
+ case PG_LEVEL_1G:
+ addr &= (~(u64)(0x0)) << 30;
+ break;
+ default:
+ return NULL;
+ }
+
+ head = kmmio_page_list(addr);
list_for_each_entry_rcu(f, head, list) {
- if (f->page == page)
+ if (f->addr == addr)
return f;
}
return NULL;
@@ -137,10 +173,10 @@
static int clear_page_presence(struct kmmio_fault_page *f, bool clear)
{
unsigned int level;
- pte_t *pte = lookup_address(f->page, &level);
+ pte_t *pte = lookup_address(f->addr, &level);
if (!pte) {
- pr_err("no pte for page 0x%08lx\n", f->page);
+ pr_err("no pte for addr 0x%08lx\n", f->addr);
return -1;
}
@@ -156,7 +192,7 @@
return -1;
}
- __flush_tlb_one(f->page);
+ __flush_tlb_one(f->addr);
return 0;
}
@@ -176,12 +212,12 @@
int ret;
WARN_ONCE(f->armed, KERN_ERR pr_fmt("kmmio page already
armed.\n"));
if (f->armed) {
- pr_warning("double-arm: page 0x%08lx, ref %d, old %d\n",
- f->page, f->count, !!f->old_presence);
+ pr_warning("double-arm: addr 0x%08lx, ref %d, old %d\n",
+ f->addr, f->count, !!f->old_presence);
}
ret = clear_page_presence(f, true);
- WARN_ONCE(ret < 0, KERN_ERR pr_fmt("arming 0x%08lx failed.\n"),
- f->page);
+ WARN_ONCE(ret < 0, KERN_ERR pr_fmt("arming at 0x%08lx
failed.\n"),
+ f->addr);
f->armed = true;
return ret;
}
@@ -191,7 +227,7 @@
{
int ret = clear_page_presence(f, false);
WARN_ONCE(ret < 0,
- KERN_ERR "kmmio disarming 0x%08lx failed.\n", f->page);
+ KERN_ERR "kmmio disarming at 0x%08lx failed.\n", f->addr);
f->armed = false;
}
@@ -215,6 +251,25 @@
struct kmmio_context *ctx;
struct kmmio_fault_page *faultpage;
int ret = 0; /* default to fault not handled */
+ unsigned long page_base = addr;
+ unsigned int l;
+ pte_t *pte = lookup_address(addr, &l);
+ if (!pte)
+ return -EINVAL;
+
+ switch (l) {
+ case PG_LEVEL_4K:
+ page_base &= (~(u64)(0x0)) << 12;
+ break;
+ case PG_LEVEL_2M:
+ page_base &= (~(u64)(0x0)) << 21;
+ break;
+ case PG_LEVEL_1G:
+ page_base &= (~(u64)(0x0)) << 30;
+ break;
+ default:
+ return -EINVAL;
+ }
/*
* Preemption is now disabled to prevent process switch during
@@ -227,7 +282,7 @@
preempt_disable();
rcu_read_lock();
- faultpage = get_kmmio_fault_page(addr);
+ faultpage = get_kmmio_fault_page(page_base);
if (!faultpage) {
/*
* Either this page fault is not caused by kmmio, or
@@ -239,7 +294,7 @@
ctx = &get_cpu_var(kmmio_ctx);
if (ctx->active) {
- if (addr == ctx->addr) {
+ if (page_base == ctx->addr) {
/*
* A second fault on the same page means some other
* condition needs handling by do_page_fault(), the
@@ -267,9 +322,9 @@
ctx->active++;
ctx->fpage = faultpage;
- ctx->probe = get_kmmio_probe(addr);
+ ctx->probe = get_kmmio_probe(page_base);
ctx->saved_flags = (regs->flags & (X86_EFLAGS_TF | X86_EFLAGS_IF));
- ctx->addr = addr;
+ ctx->addr = page_base;
if (ctx->probe && ctx->probe->pre_handler)
ctx->probe->pre_handler(ctx->probe, regs, addr);
@@ -354,12 +409,11 @@
}
/* You must be holding kmmio_lock. */
-static int add_kmmio_fault_page(unsigned long page)
+static int add_kmmio_fault_page(unsigned long addr)
{
struct kmmio_fault_page *f;
- page &= PAGE_MASK;
- f = get_kmmio_fault_page(page);
+ f = get_kmmio_fault_page(addr);
if (f) {
if (!f->count)
arm_kmmio_fault_page(f);
@@ -372,26 +426,25 @@
return -1;
f->count = 1;
- f->page = page;
+ f->addr = addr;
if (arm_kmmio_fault_page(f)) {
kfree(f);
return -1;
}
- list_add_rcu(&f->list, kmmio_page_list(f->page));
+ list_add_rcu(&f->list, kmmio_page_list(f->addr));
return 0;
}
/* You must be holding kmmio_lock. */
-static void release_kmmio_fault_page(unsigned long page,
+static void release_kmmio_fault_page(unsigned long addr,
struct kmmio_fault_page **release_list)
{
struct kmmio_fault_page *f;
- page &= PAGE_MASK;
- f = get_kmmio_fault_page(page);
+ f = get_kmmio_fault_page(addr);
if (!f)
return;
