diff mbox series

[ovs-dev,branch-2.16] dpif-netdev: Refactor AVX512 runtime checks.

Message ID 20220629133820.2001106-1-david.marchand@redhat.com
State Accepted
Commit 0fe91ee5b01b44ff9ee3e5b4a8fd02ee9506de6a
Headers show
Series [ovs-dev,branch-2.16] dpif-netdev: Refactor AVX512 runtime checks. | expand

Checks

Context Check Description
ovsrobot/apply-robot success apply and check: success
ovsrobot/intel-ovs-compilation fail test: fail
ovsrobot/github-robot-_Build_and_Test success github build: passed

Commit Message

David Marchand June 29, 2022, 1:38 p.m. UTC
[ original commit fe171e4f109f001f07b867756a261d898f0d2cfc ]

As described in the bugzilla below, cpu_has_isa code may be compiled
with some AVX512 instructions in it, because cpu.c is built as part of
the libopenvswitchavx512.
This is a problem when this function (supposed to probe for AVX512
instructions availability) is invoked from generic OVS code, on older
CPUs that don't support them.

For the same reason, dpcls_subtable_avx512_gather_probe,
dp_netdev_input_outer_avx512_probe, mfex_avx512_probe and
mfex_avx512_vbmi_probe are potential runtime bombs and can't either be
built as part of libopenvswitchavx512.

Move cpu.c to be part of the "normal" libopenvswitch.
And move other helpers in generic OVS code.

Note:
- dpcls_subtable_avx512_gather_probe is split in two, because it also
  needs to do its own magic,
- while moving those helpers, prefer direct calls to cpu_has_isa and
  avoid cast to intermediate integer variables when a simple boolean
  is enough,

Fixes: 352b6c7116cd ("dpif-lookup: add avx512 gather implementation.")
Fixes: abb807e27dd4 ("dpif-netdev: Add command to switch dpif implementation.")
Fixes: 250ceddcc2d0 ("dpif-netdev/mfex: Add AVX512 based optimized miniflow extract")
Fixes: b366fa2f4947 ("dpif-netdev: Call cpuid for x86 isa availability.")
Reported-at: https://bugzilla.redhat.com/2100393
Reported-by: Ales Musil <amusil@redhat.com>
Co-authored-by: Ales Musil <amusil@redhat.com>
Signed-off-by: Ales Musil <amusil@redhat.com>
Signed-off-by: David Marchand <david.marchand@redhat.com>
---
 lib/dpif-netdev-avx512.c               | 13 --------
 lib/dpif-netdev-extract-avx512.c       | 43 --------------------------
 lib/dpif-netdev-lookup-avx512-gather.c | 11 ++-----
 lib/dpif-netdev-lookup.c               | 14 +++++++++
 lib/dpif-netdev-lookup.h               |  3 +-
 lib/dpif-netdev-private-dpif.c         | 13 ++++++++
 lib/dpif-netdev-private-dpif.h         |  5 +--
 lib/dpif-netdev-private-extract.c      | 37 ++++++++++++++++++++++
 lib/dpif-netdev-private-extract.h      |  4 +--
 9 files changed, 70 insertions(+), 73 deletions(-)

Comments

Ilya Maximets June 29, 2022, 6:32 p.m. UTC | #1
On 6/29/22 15:38, David Marchand wrote:
> [ original commit fe171e4f109f001f07b867756a261d898f0d2cfc ]
> 
> As described in the bugzilla below, cpu_has_isa code may be compiled
> with some AVX512 instructions in it, because cpu.c is built as part of
> the libopenvswitchavx512.
> This is a problem when this function (supposed to probe for AVX512
> instructions availability) is invoked from generic OVS code, on older
> CPUs that don't support them.
> 
> For the same reason, dpcls_subtable_avx512_gather_probe,
> dp_netdev_input_outer_avx512_probe, mfex_avx512_probe and
> mfex_avx512_vbmi_probe are potential runtime bombs and can't either be
> built as part of libopenvswitchavx512.
> 
> Move cpu.c to be part of the "normal" libopenvswitch.
> And move other helpers in generic OVS code.
> 
> Note:
> - dpcls_subtable_avx512_gather_probe is split in two, because it also
>   needs to do its own magic,
> - while moving those helpers, prefer direct calls to cpu_has_isa and
>   avoid cast to intermediate integer variables when a simple boolean
>   is enough,
> 
> Fixes: 352b6c7116cd ("dpif-lookup: add avx512 gather implementation.")
> Fixes: abb807e27dd4 ("dpif-netdev: Add command to switch dpif implementation.")
> Fixes: 250ceddcc2d0 ("dpif-netdev/mfex: Add AVX512 based optimized miniflow extract")
> Fixes: b366fa2f4947 ("dpif-netdev: Call cpuid for x86 isa availability.")
> Reported-at: https://bugzilla.redhat.com/2100393
> Reported-by: Ales Musil <amusil@redhat.com>
> Co-authored-by: Ales Musil <amusil@redhat.com>
> Signed-off-by: Ales Musil <amusil@redhat.com>
> Signed-off-by: David Marchand <david.marchand@redhat.com>
> ---

Thanks, David!
I applied all backports to appropriate branches.

Best regards, Ilya Maximets.
diff mbox series

Patch

diff --git a/lib/dpif-netdev-avx512.c b/lib/dpif-netdev-avx512.c
index 544d36903e..01011f679a 100644
--- a/lib/dpif-netdev-avx512.c
+++ b/lib/dpif-netdev-avx512.c
@@ -58,19 +58,6 @@  struct dpif_userdata {
         struct pkt_flow_meta pkt_meta[NETDEV_MAX_BURST];
 };
 
-int32_t
-dp_netdev_input_outer_avx512_probe(void)
-{
-    bool avx512f_available = dpdk_get_cpu_has_isa("x86_64", "avx512f");
-    bool bmi2_available = dpdk_get_cpu_has_isa("x86_64", "bmi2");
-
-    if (!avx512f_available || !bmi2_available) {
-        return -ENOTSUP;
-    }
-
-    return 0;
-}
-
 int32_t
 dp_netdev_input_outer_avx512(struct dp_netdev_pmd_thread *pmd,
                              struct dp_packet_batch *packets,
diff --git a/lib/dpif-netdev-extract-avx512.c b/lib/dpif-netdev-extract-avx512.c
index 28b54ef2f1..993d07e401 100644
--- a/lib/dpif-netdev-extract-avx512.c
+++ b/lib/dpif-netdev-extract-avx512.c
@@ -43,7 +43,6 @@ 
 #include <string.h>
 
 #include "flow.h"
-#include "dpdk.h"
 
 #include "dpif-netdev-private-dpcls.h"
 #include "dpif-netdev-private-extract.h"
@@ -663,47 +662,5 @@  DECLARE_MFEX_FUNC(ip_udp, PROFILE_ETH_IPV4_UDP)
 DECLARE_MFEX_FUNC(ip_tcp, PROFILE_ETH_IPV4_TCP)
 DECLARE_MFEX_FUNC(dot1q_ip_udp, PROFILE_ETH_VLAN_IPV4_UDP)
 DECLARE_MFEX_FUNC(dot1q_ip_tcp, PROFILE_ETH_VLAN_IPV4_TCP)
-
-
-static int32_t
-avx512_isa_probe(uint32_t needs_vbmi)
-{
-    static const char *isa_required[] = {
-        "avx512f",
-        "avx512bw",
-        "bmi2",
-    };
-
-    int32_t ret = 0;
-    for (uint32_t i = 0; i < ARRAY_SIZE(isa_required); i++) {
-        if (!dpdk_get_cpu_has_isa("x86_64", isa_required[i])) {
-            ret = -ENOTSUP;
-        }
-    }
-
-    if (needs_vbmi) {
-        if (!dpdk_get_cpu_has_isa("x86_64", "avx512vbmi")) {
-            ret = -ENOTSUP;
-        }
-    }
-
-    return ret;
-}
-
-/* Probe functions to check ISA requirements. */
-int32_t
-mfex_avx512_probe(void)
-{
-    const uint32_t needs_vbmi = 0;
-    return avx512_isa_probe(needs_vbmi);
-}
-
-int32_t
-mfex_avx512_vbmi_probe(void)
-{
-    const uint32_t needs_vbmi = 1;
-    return avx512_isa_probe(needs_vbmi);
-}
-
 #endif /* __CHECKER__ */
 #endif /* __x86_64__ */
diff --git a/lib/dpif-netdev-lookup-avx512-gather.c b/lib/dpif-netdev-lookup-avx512-gather.c
index 072831e96a..154f9318d4 100644
--- a/lib/dpif-netdev-lookup-avx512-gather.c
+++ b/lib/dpif-netdev-lookup-avx512-gather.c
@@ -394,18 +394,11 @@  dpcls_avx512_gather_mf_any(struct dpcls_subtable *subtable, uint32_t keys_map,
 }
 
 dpcls_subtable_lookup_func
-dpcls_subtable_avx512_gather_probe(uint32_t u0_bits, uint32_t u1_bits)
+dpcls_subtable_avx512_gather_probe__(uint32_t u0_bits, uint32_t u1_bits,
+                                     bool use_vpop)
 {
     dpcls_subtable_lookup_func f = NULL;
 
-    int avx512f_available = dpdk_get_cpu_has_isa("x86_64", "avx512f");
-    int bmi2_available = dpdk_get_cpu_has_isa("x86_64", "bmi2");
-    if (!avx512f_available || !bmi2_available) {
-        return NULL;
-    }
-
-    int use_vpop = dpdk_get_cpu_has_isa("x86_64", "avx512vpopcntdq");
-
     CHECK_LOOKUP_FUNCTION(9, 4, use_vpop);
     CHECK_LOOKUP_FUNCTION(9, 1, use_vpop);
     CHECK_LOOKUP_FUNCTION(5, 3, use_vpop);
diff --git a/lib/dpif-netdev-lookup.c b/lib/dpif-netdev-lookup.c
index bd0a99abe7..5cb52386f2 100644
--- a/lib/dpif-netdev-lookup.c
+++ b/lib/dpif-netdev-lookup.c
@@ -22,6 +22,20 @@ 
 
 VLOG_DEFINE_THIS_MODULE(dpif_netdev_lookup);
 
+#if (__x86_64__ && HAVE_AVX512F && HAVE_LD_AVX512_GOOD && __SSE4_2__)
+static dpcls_subtable_lookup_func
+dpcls_subtable_avx512_gather_probe(uint32_t u0_bits, uint32_t u1_bits)
+{
+    if (!dpdk_get_cpu_has_isa("x86_64", "avx512f")
+        || !dpdk_get_cpu_has_isa("x86_64", "bmi2")) {
+        return NULL;
+    }
+
+    return dpcls_subtable_avx512_gather_probe__(u0_bits, u1_bits,
+        dpdk_get_cpu_has_isa("x86_64", "avx512vpopcntdq"));
+}
+#endif
+
 /* Actual list of implementations goes here */
 static struct dpcls_subtable_lookup_info_t subtable_lookups[] = {
     /* The autovalidator implementation will not be used by default, it must
diff --git a/lib/dpif-netdev-lookup.h b/lib/dpif-netdev-lookup.h
index 59f51faa0e..5d2d845945 100644
--- a/lib/dpif-netdev-lookup.h
+++ b/lib/dpif-netdev-lookup.h
@@ -44,7 +44,8 @@  dpcls_subtable_generic_probe(uint32_t u0_bit_count, uint32_t u1_bit_count);
 
 /* Probe function for AVX-512 gather implementation */
 dpcls_subtable_lookup_func
-dpcls_subtable_avx512_gather_probe(uint32_t u0_bit_cnt, uint32_t u1_bit_cnt);
+dpcls_subtable_avx512_gather_probe__(uint32_t u0_bit_cnt, uint32_t u1_bit_cnt,
+                                     bool use_vpop);
 
 
 /* Subtable registration and iteration helpers */
diff --git a/lib/dpif-netdev-private-dpif.c b/lib/dpif-netdev-private-dpif.c
index 84d4ec156e..ac40757281 100644
--- a/lib/dpif-netdev-private-dpif.c
+++ b/lib/dpif-netdev-private-dpif.c
@@ -33,6 +33,19 @@  enum dpif_netdev_impl_info_idx {
     DPIF_NETDEV_IMPL_AVX512
 };
 
+#if (__x86_64__ && HAVE_AVX512F && HAVE_LD_AVX512_GOOD && __SSE4_2__)
+static int32_t
+dp_netdev_input_outer_avx512_probe(void)
+{
+    if (!dpdk_get_cpu_has_isa("x86_64", "avx512f")
+        || !dpdk_get_cpu_has_isa("x86_64", "bmi2")) {
+        return -ENOTSUP;
+    }
+
+    return 0;
+}
+#endif
+
 /* Actual list of implementations goes here. */
 static struct dpif_netdev_impl_info_t dpif_impls[] = {
     /* The default scalar C code implementation. */
diff --git a/lib/dpif-netdev-private-dpif.h b/lib/dpif-netdev-private-dpif.h
index 0da639c55a..3e38630f53 100644
--- a/lib/dpif-netdev-private-dpif.h
+++ b/lib/dpif-netdev-private-dpif.h
@@ -67,10 +67,7 @@  dp_netdev_input(struct dp_netdev_pmd_thread *pmd,
                 struct dp_packet_batch *packets,
                 odp_port_t in_port);
 
-/* AVX512 enabled DPIF implementation and probe functions. */
-int32_t
-dp_netdev_input_outer_avx512_probe(void);
-
+/* AVX512 enabled DPIF implementation function. */
 int32_t
 dp_netdev_input_outer_avx512(struct dp_netdev_pmd_thread *pmd,
                              struct dp_packet_batch *packets,
diff --git a/lib/dpif-netdev-private-extract.c b/lib/dpif-netdev-private-extract.c
index 7a06dbf6fd..245d1c0cad 100644
--- a/lib/dpif-netdev-private-extract.c
+++ b/lib/dpif-netdev-private-extract.c
@@ -33,6 +33,43 @@  VLOG_DEFINE_THIS_MODULE(dpif_netdev_extract);
 /* Variable to hold the default MFEX implementation. */
 static ATOMIC(miniflow_extract_func) default_mfex_func;
 
+#if (__x86_64__ && HAVE_AVX512F && HAVE_LD_AVX512_GOOD && __SSE4_2__)
+static int32_t
+avx512_isa_probe(bool needs_vbmi)
+{
+    static const char *isa_required[] = {
+        "avx512f",
+        "avx512bw",
+        "bmi2",
+    };
+
+    for (uint32_t i = 0; i < ARRAY_SIZE(isa_required); i++) {
+        if (!dpdk_get_cpu_has_isa("x86_64", isa_required[i])) {
+            return -ENOTSUP;
+        }
+    }
+
+    if (needs_vbmi && !dpdk_get_cpu_has_isa("x86_64", "avx512vbmi")) {
+        return -ENOTSUP;
+    }
+
+    return 0;
+}
+
+/* Probe functions to check ISA requirements. */
+static int32_t
+mfex_avx512_probe(void)
+{
+    return avx512_isa_probe(false);
+}
+
+static int32_t
+mfex_avx512_vbmi_probe(void)
+{
+    return avx512_isa_probe(true);
+}
+#endif
+
 /* Implementations of available extract options and
  * the implementations are always in order of preference.
  */
diff --git a/lib/dpif-netdev-private-extract.h b/lib/dpif-netdev-private-extract.h
index f9a757ba41..3e06148c5a 100644
--- a/lib/dpif-netdev-private-extract.h
+++ b/lib/dpif-netdev-private-extract.h
@@ -176,10 +176,8 @@  mfex_study_traffic(struct dp_packet_batch *packets,
 int
 mfex_set_study_pkt_cnt(uint32_t pkt_cmp_count, const char *name);
 
-/* AVX512 MFEX Probe and Implementations functions. */
+/* AVX512 MFEX Implementation functions. */
 #ifdef __x86_64__
-int32_t mfex_avx512_probe(void);
-int32_t mfex_avx512_vbmi_probe(void);
 
 #define DECLARE_AVX512_MFEX_PROTOTYPE(name)                                 \
     uint32_t                                                                \