diff mbox series

[v4,3/8] i386: Add RDT functionality

Message ID 20241205200025.2081863-4-whendrik@google.com (mailing list archive)
State New
Headers show
Series Emulate Intel RDT features needed to mount ResCtrl in Linux | expand

Commit Message

Hendrik Wuethrich Dec. 5, 2024, 8 p.m. UTC 
From: ‪Hendrik Wüthrich <whendrik@google.com>

Add RDT code to Associate CLOSID with RMID / set RMID for monitoring,
write COS, and read monitoring data. This patch does not add code for
the guest to interact through these things with MSRs, only the actual
ability for the RDT device to do them.

Signed-off-by: Hendrik Wüthrich <whendrik@google.com>
---
 hw/i386/rdt.c         | 123 ++++++++++++++++++++++++++++++++++++++++++
 include/hw/i386/rdt.h |  16 ++++++
 2 files changed, 139 insertions(+)
diff mbox series

Patch

diff --git a/hw/i386/rdt.c b/hw/i386/rdt.c
index 920e9c5dbe..01bee79cbe 100644
--- a/hw/i386/rdt.c
+++ b/hw/i386/rdt.c
@@ -21,6 +21,11 @@ 
 #include "qom/object.h"
 #include "target/i386/cpu.h"
 
+/* RDT Monitoring Event Codes */
+#define RDT_EVENT_L3_OCCUPANCY 1
+#define RDT_EVENT_L3_REMOTE_BW 2
+#define RDT_EVENT_L3_LOCAL_BW 3
+
 /* Max counts for allocation masks or CBMs. In other words, the size of
  * respective MSRs.
  * L3_MASK and L3_mask are architectural limitations. THRTL_COUNT is just
@@ -33,6 +38,9 @@ 
 #define TYPE_RDT "rdt"
 #define RDT_NUM_RMID_PROP "rmids"
 
+#define QM_CTR_ERROR        (1ULL << 63)
+#define QM_CTR_UNAVAILABLE  (1ULL << 62)
+
 OBJECT_DECLARE_TYPE(RDTState, RDTStateClass, RDT);
 
 struct RDTMonitor {
@@ -73,6 +81,121 @@  struct RDTState {
 struct RDTStateClass {
 };
 
+bool rdt_associate_rmid_cos(uint64_t msr_ia32_pqr_assoc)
+{
+    X86CPU *cpu = X86_CPU(current_cpu);
+    RDTStatePerCore *rdt = cpu->rdt;
+    RDTAllocation *alloc;
+
+    uint32_t cos_id = (msr_ia32_pqr_assoc & 0xffff0000) >> 16;
+    uint32_t rmid = msr_ia32_pqr_assoc & 0xffff;
+
+    if (cos_id > RDT_MAX_L3_MASK_COUNT || cos_id > RDT_MAX_L2_MASK_COUNT ||
+        cos_id > RDT_MAX_MBA_THRTL_COUNT || rmid > rdt_max_rmid(rdt)) {
+        return false;
+    }
+
+    rdt->active_rmid = rmid;
+
+    alloc = &rdt->rdtstate->allocations[rmid];
+
+    alloc->active_cos = cos_id;
+
+    return true;
+}
+
+uint32_t rdt_read_l3_mask(uint32_t pos)
+{
+    X86CPU *cpu = X86_CPU(current_cpu);
+    RDTStatePerCore *rdt = cpu->rdt;
+
+    return rdt->rdtstate->msr_L3_ia32_mask_n[pos];
+}
+
+uint32_t rdt_read_l2_mask(uint32_t pos)
+{
+    X86CPU *cpu = X86_CPU(current_cpu);
+    RDTStatePerCore *rdt = cpu->rdt;
+
+    return rdt->rdtstate->msr_L2_ia32_mask_n[pos];
+}
+
+uint32_t rdt_read_mba_thrtl(uint32_t pos)
+{
+    X86CPU *cpu = X86_CPU(current_cpu);
+    RDTStatePerCore *rdt = cpu->rdt;
+
+    return rdt->rdtstate->ia32_L2_qos_ext_bw_thrtl_n[pos];
+}
+
+void rdt_write_msr_l3_mask(uint32_t pos, uint32_t val)
+{
+    X86CPU *cpu = X86_CPU(current_cpu);
+    RDTStatePerCore *rdt = cpu->rdt;
+
+    rdt->rdtstate->msr_L3_ia32_mask_n[pos] = val;
+}
+
+void rdt_write_msr_l2_mask(uint32_t pos, uint32_t val)
+{
+    X86CPU *cpu = X86_CPU(current_cpu);
+    RDTStatePerCore *rdt = cpu->rdt;
+
+    rdt->rdtstate->msr_L2_ia32_mask_n[pos] = val;
+}
+
+void rdt_write_mba_thrtl(uint32_t pos, uint32_t val)
+{
+    X86CPU *cpu = X86_CPU(current_cpu);
+    RDTStatePerCore *rdt = cpu->rdt;
+
+    rdt->rdtstate->ia32_L2_qos_ext_bw_thrtl_n[pos] = val;
+}
+
+uint32_t rdt_max_rmid(RDTStatePerCore *rdt)
+{
+    RDTState *rdtdev = rdt->rdtstate;
+    return rdtdev->rmids - 1;
+}
+
+uint64_t rdt_read_event_count(RDTStatePerCore *rdtInstance,
+                              uint32_t rmid, uint32_t event_id)
+{
+    CPUState *cs;
+    RDTMonitor *mon;
+    RDTState *rdt = rdtInstance->rdtstate;
+
+    uint32_t count_l3 = 0;
+    uint32_t count_local = 0;
+    uint32_t count_remote = 0;
+
+    if (!rdt) {
+        return 0;
+    }
+
+    CPU_FOREACH(cs) {
+        rdtInstance = &rdt->rdtInstances[cs->cpu_index];
+        if (rmid >= rdtInstance->monitors->len) {
+            return QM_CTR_ERROR;
+        }
+        mon = &g_array_index(rdtInstance->monitors, RDTMonitor, rmid);
+        count_l3 += mon->count_l3;
+        count_local += mon->count_local;
+        count_remote += mon->count_remote;
+    }
+
+    switch (event_id) {
+    case RDT_EVENT_L3_OCCUPANCY:
+        return count_l3 == 0 ? QM_CTR_UNAVAILABLE : count_l3;
+    case RDT_EVENT_L3_REMOTE_BW:
+        return count_remote == 0 ? QM_CTR_UNAVAILABLE : count_remote;
+    case RDT_EVENT_L3_LOCAL_BW:
+        return count_local == 0 ? QM_CTR_UNAVAILABLE : count_local;
+    default:
+        return QM_CTR_ERROR;
+    }
+}
+
 OBJECT_DEFINE_TYPE(RDTState, rdt, RDT, ISA_DEVICE);
 
 static Property rdt_properties[] = {
diff --git a/include/hw/i386/rdt.h b/include/hw/i386/rdt.h
index a21d95b265..14b1c64b72 100644
--- a/include/hw/i386/rdt.h
+++ b/include/hw/i386/rdt.h
@@ -17,9 +17,25 @@ 
 #ifndef HW_RDT_H
 #define HW_RDT_H
 
+#include <stdbool.h>
+#include <stdint.h>
+
 typedef struct RDTState RDTState;
 typedef struct RDTStatePerCore RDTStatePerCore;
 typedef struct RDTMonitor RDTMonitor;
 typedef struct RDTAllocation RDTAllocation;
 
+bool rdt_associate_rmid_cos(uint64_t msr_ia32_pqr_assoc);
+
+void rdt_write_msr_l3_mask(uint32_t pos, uint32_t val);
+void rdt_write_msr_l2_mask(uint32_t pos, uint32_t val);
+void rdt_write_mba_thrtl(uint32_t pos, uint32_t val);
+
+uint32_t rdt_read_l3_mask(uint32_t pos);
+uint32_t rdt_read_l2_mask(uint32_t pos);
+uint32_t rdt_read_mba_thrtl(uint32_t pos);
+
+uint64_t rdt_read_event_count(RDTStatePerCore *rdt, uint32_t rmid, uint32_t event_id);
+uint32_t rdt_max_rmid(RDTStatePerCore *rdt);
+
 #endif