diff mbox series

[v2,4/8] i386: Add RDT device interface through MSRs

Message ID 20240905112237.3586972-5-whendrik@google.com
State New
Headers show
Series target:386/ Emulate Intel RDT features needed to mount ResCtrl in Linux | expand

Commit Message

Hendrik Wuethrich Sept. 5, 2024, 11:22 a.m. UTC 
From: ‪Hendrik Wüthrich <whendrik@google.com>

Implement rdmsr and wrmsr for the following MSRs:
* MSR_IA32_PQR_ASSOC
* MSR_IA32_QM_EVTSEL
* MSR_IA32_QM_CTR
* IA32_L3_QOS_Mask_n
* IA32_L2_QOS_Mask_n
* IA32_L2_QoS_Ext_BW_Thrtl_n

This allows for the guest to call RDT-internal functions to
associate an RMID with a CLOSID / set an active RMID for
monitoring, read monitoring data, and set classes of service.

Signed-off-by: Hendrik Wüthrich <whendrik@google.com>
---
 hw/i386/rdt.c                        | 22 ++++----
 include/hw/i386/rdt.h                |  4 ++
 target/i386/cpu.h                    | 14 +++++
 target/i386/tcg/sysemu/misc_helper.c | 84 ++++++++++++++++++++++++++++
 4 files changed, 112 insertions(+), 12 deletions(-)
diff mbox series

Patch

diff --git a/hw/i386/rdt.c b/hw/i386/rdt.c
index 288f1fd107..d3713073c5 100644
--- a/hw/i386/rdt.c
+++ b/hw/i386/rdt.c
@@ -77,6 +77,10 @@  struct RDTState {
 struct RDTStateClass {
 };
 
+uint32_t rdt_get_cpuid_10_1_edx_cos_max(void) { return RDT_MAX_L3_MASK_COUNT; }
+uint32_t rdt_get_cpuid_10_2_edx_cos_max(void) { return RDT_MAX_L2_MASK_COUNT; }
+uint32_t rdt_get_cpuid_10_3_edx_cos_max(void) { return RDT_MAX_MBA_THRTL_COUNT; }
+
 bool rdt_associate_rmid_cos(uint64_t msr_ia32_pqr_assoc) {
     X86CPU *cpu = X86_CPU(current_cpu);
     RDTStatePerCore *rdt = cpu->rdt;
@@ -86,7 +90,7 @@  bool rdt_associate_rmid_cos(uint64_t msr_ia32_pqr_assoc) {
     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)) {
+        cos_id > RDT_MAX_MBA_THRTL_COUNT || rmid > rdt_max_rmid(rdt)) {
         return false;
     }
 
@@ -104,8 +108,7 @@  uint32_t rdt_read_l3_mask(uint32_t pos)
     X86CPU *cpu = X86_CPU(current_cpu);
     RDTStatePerCore *rdt = cpu->rdt;
 
-    uint32_t val = rdt->rdtstate->msr_L3_ia32_mask_n[pos];
-    return val;
+    return rdt->rdtstate->msr_L3_ia32_mask_n[pos];
 }
 
 uint32_t rdt_read_l2_mask(uint32_t pos)
@@ -113,8 +116,7 @@  uint32_t rdt_read_l2_mask(uint32_t pos)
     X86CPU *cpu = X86_CPU(current_cpu);
     RDTStatePerCore *rdt = cpu->rdt;
 
-    uint32_t val = rdt->rdtstate->msr_L2_ia32_mask_n[pos];
-    return val;
+    return rdt->rdtstate->msr_L2_ia32_mask_n[pos];
 }
 
 uint32_t rdt_read_mba_thrtl(uint32_t pos)
@@ -122,8 +124,7 @@  uint32_t rdt_read_mba_thrtl(uint32_t pos)
     X86CPU *cpu = X86_CPU(current_cpu);
     RDTStatePerCore *rdt = cpu->rdt;
 
-    uint32_t val = rdt->rdtstate->ia32_L2_qos_ext_bw_thrtl_n[pos];
-    return val;
+    return rdt->rdtstate->ia32_L2_qos_ext_bw_thrtl_n[pos];
 }
 
 void rdt_write_msr_l3_mask(uint32_t pos, uint32_t val) {
@@ -153,7 +154,8 @@  uint32_t rdt_max_rmid(RDTStatePerCore *rdt)
     return rdtdev->rmids - 1;
 }
 
-uint64_t rdt_read_event_count(RDTStatePerCore *rdtInstance, uint32_t rmid, uint32_t event_id)
+uint64_t rdt_read_event_count(RDTStatePerCore *rdtInstance,
+                              uint32_t rmid, uint32_t event_id)
 {
     CPUState *cs;
     RDTMonitor *mon;
@@ -181,13 +183,10 @@  uint64_t rdt_read_event_count(RDTStatePerCore *rdtInstance, uint32_t rmid, uint3
     switch (event_id) {
         case RDT_EVENT_L3_OCCUPANCY:
             return count_l3 == 0 ? QM_CTR_UNAVAILABLE : count_l3;
-            break;
         case RDT_EVENT_L3_REMOTE_BW:
             return count_remote == 0 ? QM_CTR_UNAVAILABLE : count_remote;
-            break;
         case RDT_EVENT_L3_LOCAL_BW:
             return count_local == 0 ? QM_CTR_UNAVAILABLE : count_local;
-            break;
         default:
             return QM_CTR_ERROR;
     }
@@ -247,4 +246,3 @@  static void rdt_class_init(ObjectClass *klass, void *data)
 
     device_class_set_props(dc, rdt_properties);
 }
-
diff --git a/include/hw/i386/rdt.h b/include/hw/i386/rdt.h
index 14b1c64b72..ec82a149f2 100644
--- a/include/hw/i386/rdt.h
+++ b/include/hw/i386/rdt.h
@@ -25,6 +25,10 @@  typedef struct RDTStatePerCore RDTStatePerCore;
 typedef struct RDTMonitor RDTMonitor;
 typedef struct RDTAllocation RDTAllocation;
 
+uint32_t rdt_get_cpuid_10_1_edx_cos_max(void);
+uint32_t rdt_get_cpuid_10_2_edx_cos_max(void);
+uint32_t rdt_get_cpuid_10_3_edx_cos_max(void);
+
 bool rdt_associate_rmid_cos(uint64_t msr_ia32_pqr_assoc);
 
 void rdt_write_msr_l3_mask(uint32_t pos, uint32_t val);
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index a2941f98eb..e722fd4622 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -574,6 +574,17 @@  typedef enum X86Seg {
 #define MSR_IA32_VMX_TRUE_ENTRY_CTLS     0x00000490
 #define MSR_IA32_VMX_VMFUNC             0x00000491
 
+#define MSR_IA32_QM_EVTSEL                  0x0c8d
+#define MSR_IA32_QM_CTR                     0x0c8e
+#define MSR_IA32_PQR_ASSOC                  0x0c8f
+
+#define MSR_IA32_L3_CBM_BASE                0x0c90
+#define MSR_IA32_L3_MASKS_END               0x0d0f
+#define MSR_IA32_L2_CBM_BASE                0x0d10
+#define MSR_IA32_L2_CBM_END                 0x0d4f
+#define MSR_IA32_L2_QOS_Ext_BW_Thrtl_BASE   0xd50
+#define MSR_IA32_L2_QOS_Ext_BW_Thrtl_END    0xd80
+
 #define MSR_APIC_START                  0x00000800
 #define MSR_APIC_END                    0x000008ff
 
@@ -1778,6 +1789,9 @@  typedef struct CPUArchState {
     uint64_t msr_ia32_feature_control;
     uint64_t msr_ia32_sgxlepubkeyhash[4];
 
+    uint64_t msr_ia32_qm_evtsel;
+    uint64_t msr_ia32_pqr_assoc;
+
     uint64_t msr_fixed_ctr_ctrl;
     uint64_t msr_global_ctrl;
     uint64_t msr_global_status;
diff --git a/target/i386/tcg/sysemu/misc_helper.c b/target/i386/tcg/sysemu/misc_helper.c
index 094aa56a20..bbfd5c0219 100644
--- a/target/i386/tcg/sysemu/misc_helper.c
+++ b/target/i386/tcg/sysemu/misc_helper.c
@@ -25,6 +25,7 @@ 
 #include "exec/address-spaces.h"
 #include "exec/exec-all.h"
 #include "tcg/helper-tcg.h"
+#include "hw/i386/rdt.h"
 #include "hw/i386/apic.h"
 
 void helper_outb(CPUX86State *env, uint32_t port, uint32_t data)
@@ -293,6 +294,47 @@  void helper_wrmsr(CPUX86State *env)
         env->msr_bndcfgs = val;
         cpu_sync_bndcs_hflags(env);
         break;
+    case MSR_IA32_QM_EVTSEL:
+        env->msr_ia32_qm_evtsel = val;
+        break;
+    case MSR_IA32_PQR_ASSOC:
+    {
+        env->msr_ia32_pqr_assoc = val;
+
+        if (!rdt_associate_rmid_cos(val))
+            goto error;
+        break;
+    }
+    case MSR_IA32_L3_CBM_BASE ... MSR_IA32_L3_MASKS_END:
+    {
+        uint32_t pos = (uint32_t)env->regs[R_ECX] - MSR_IA32_L3_CBM_BASE;
+
+        if (pos >= rdt_get_cpuid_10_1_edx_cos_max()) {
+            goto error;
+        }
+        rdt_write_msr_l3_mask(pos, val);
+        break;
+    }
+    case MSR_IA32_L2_CBM_BASE ... MSR_IA32_L2_CBM_END:
+    {
+        uint32_t pos = (uint32_t)env->regs[R_ECX] - MSR_IA32_L2_CBM_BASE;
+
+        if (pos >= rdt_get_cpuid_10_2_edx_cos_max()) {
+            goto error;
+        }
+        rdt_write_msr_l2_mask(pos, val);
+        break;
+    }
+    case MSR_IA32_L2_QOS_Ext_BW_Thrtl_BASE ... MSR_IA32_L2_QOS_Ext_BW_Thrtl_END:
+    {
+        uint32_t pos = (uint32_t)env->regs[R_ECX] - MSR_IA32_L2_QOS_Ext_BW_Thrtl_BASE;
+
+        if (pos >= rdt_get_cpuid_10_3_edx_cos_max()) {
+            goto error;
+        }
+        rdt_write_mba_thrtl(pos, val);
+        break;
+    }
     case MSR_APIC_START ... MSR_APIC_END: {
         int ret;
         int index = (uint32_t)env->regs[R_ECX] - MSR_APIC_START;
@@ -472,6 +514,47 @@  void helper_rdmsr(CPUX86State *env)
         val = (cs->nr_threads * cs->nr_cores) | (cs->nr_cores << 16);
         break;
     }
+    case MSR_IA32_QM_CTR:
+        val = rdt_read_event_count(x86_cpu->rdt,
+                                   (env->msr_ia32_qm_evtsel >> 32) & 0xff,
+                                   env->msr_ia32_qm_evtsel & 0xff);
+        break;
+    case MSR_IA32_QM_EVTSEL:
+        val = env->msr_ia32_qm_evtsel;
+        break;
+    case MSR_IA32_PQR_ASSOC:
+        val = env->msr_ia32_pqr_assoc;
+        break;
+    case MSR_IA32_L3_CBM_BASE ... MSR_IA32_L3_MASKS_END:
+    {
+        uint32_t pos = (uint32_t)env->regs[R_ECX] - MSR_IA32_L3_CBM_BASE;
+
+        if (pos >= rdt_get_cpuid_10_1_edx_cos_max()) {
+            raise_exception_err_ra(env, EXCP0D_GPF, 0, GETPC());
+        }
+        val = rdt_read_l3_mask(pos);
+        break;
+    }
+    case MSR_IA32_L2_CBM_BASE ... MSR_IA32_L2_CBM_END:
+    {
+        uint32_t pos = (uint32_t)env->regs[R_ECX] - MSR_IA32_L2_CBM_BASE;
+
+        if (pos >= rdt_get_cpuid_10_2_edx_cos_max()) {
+            raise_exception_err_ra(env, EXCP0D_GPF, 0, GETPC());  
+        }
+        val = rdt_read_l2_mask(pos);
+        break;
+    }
+    case MSR_IA32_L2_QOS_Ext_BW_Thrtl_BASE ... MSR_IA32_L2_QOS_Ext_BW_Thrtl_END:
+    {
+        uint32_t pos = (uint32_t)env->regs[R_ECX] - MSR_IA32_L2_QOS_Ext_BW_Thrtl_BASE;
+
+        if (pos >= rdt_get_cpuid_10_3_edx_cos_max()) {
+            raise_exception_err_ra(env, EXCP0D_GPF, 0, GETPC());
+        }
+        val = rdt_read_mba_thrtl(pos);
+        break;
+    }
     case MSR_APIC_START ... MSR_APIC_END: {
         int ret;
         int index = (uint32_t)env->regs[R_ECX] - MSR_APIC_START;
@@ -499,6 +582,7 @@  void helper_rdmsr(CPUX86State *env)
     }
     env->regs[R_EAX] = (uint32_t)(val);
     env->regs[R_EDX] = (uint32_t)(val >> 32);
+    return;
 }
 
 void helper_flush_page(CPUX86State *env, target_ulong addr)