On Thu, Jan 23, 2020 at 10:04:33AM -0800, Ben Gardon wrote:
Most VMs have multiple vCPUs, the concurrent execution of which has a substantial impact on demand paging performance. Add an option to create multiple vCPUs to each access disjoint regions of memory.
Signed-off-by: Ben Gardon bgardon@google.com
.../selftests/kvm/demand_paging_test.c | 255 ++++++++++++------ 1 file changed, 172 insertions(+), 83 deletions(-)
diff --git a/tools/testing/selftests/kvm/demand_paging_test.c b/tools/testing/selftests/kvm/demand_paging_test.c index 9e2a5f7dfa140..2002032df32cc 100644 --- a/tools/testing/selftests/kvm/demand_paging_test.c +++ b/tools/testing/selftests/kvm/demand_paging_test.c @@ -24,8 +24,6 @@ #include "kvm_util.h" #include "processor.h" -#define VCPU_ID 1
/* The memory slot index demand page */ #define TEST_MEM_SLOT_INDEX 1 @@ -34,6 +32,14 @@ #define DEFAULT_GUEST_TEST_MEM_SIZE (1 << 30) /* 1G */ +#ifdef PRINT_PER_VCPU_UPDATES +#define PER_VCPU_DEBUG(...) DEBUG(__VA_ARGS__) +#else +#define PER_VCPU_DEBUG(...) +#endif
+#define MAX_VCPUS 512
/*
- Guest/Host shared variables. Ensure addr_gva2hva() and/or
- sync_global_to/from_guest() are used when accessing from
@@ -67,18 +73,25 @@ struct vcpu_args { struct kvm_vm *vm; }; -static struct vcpu_args vcpu_args; +static struct vcpu_args vcpu_args[MAX_VCPUS]; /*
- Continuously write to the first 8 bytes of each page in the demand paging
- memory region.
*/ -static void guest_code(void) +static void guest_code(uint32_t vcpu_id) {
- uint64_t gva = vcpu_args.gva;
- uint64_t pages = vcpu_args.pages;
- uint64_t gva;
- uint64_t pages; int i;
- /* Return to signal error if vCPU args data structure is courrupt. */
- if (vcpu_args[vcpu_id].vcpu_id != vcpu_id)
return;
This should be GUEST_ASSERT(vcpu_args[vcpu_id].vcpu_id == vcpu_id), which will do a UCALL_ABORT when it fails. Otherwise we're returning to where? Likely we'll get an exception of some sort when we return to nothing, but that's not a very clean way to die.
Thanks, drew