hypervisor: Add disk bandwidth and operations rate limiters

This is the disk counterpart of the what was introduced for the network
as part of the previous commits in this series.

The newly added fields are:
* DiskRateLimiterBwMaxRate, defined in bits per second, which is used to
  control the network I/O bandwidth at the VM level.
* DiskRateLimiterBwOneTimeBurst, also defined in bits per second, which
  is used to define an *initial* max rate, which doesn't replenish.
* DiskRateLimiterOpsMaxRate, the operations per second equivalent of the
  DiskRateLimiterBwMaxRate.
* DiskRateLimiterOpsOneTimeBurst, the operations per second equivalent of
  the DiskRateLimiterBwOneTimeBurst.

For now those extra fields have only been added to the hypervisor's
configuration and they'll be used in the coming patches of this very
same series.

Signed-off-by: Fabiano Fidêncio <fabiano.fidencio@intel.com>

src/runtime/pkg/katautils/config.go

@@ -108,6 +108,10 @@ type hypervisor struct {
 	RxRateLimiterMaxRate           uint64   `toml:"rx_rate_limiter_max_rate"`
 	TxRateLimiterMaxRate           uint64   `toml:"tx_rate_limiter_max_rate"`
 	MemOffset                      uint64   `toml:"memory_offset"`
+	DiskRateLimiterBwMaxRate       int64    `toml:"disk_rate_limiter_bw_max_rate"`
+	DiskRateLimiterBwOneTimeBurst  int64    `toml:"disk_rate_limiter_bw_one_time_burst"`
+	DiskRateLimiterOpsMaxRate      int64    `toml:"disk_rate_limiter_ops_max_rate"`
+	DiskRateLimiterOpsOneTimeBurst int64    `toml:"disk_rate_limiter_ops_one_time_burst"`
 	NetRateLimiterBwMaxRate        int64    `toml:"net_rate_limiter_bw_max_rate"`
 	NetRateLimiterBwOneTimeBurst   int64    `toml:"net_rate_limiter_bw_one_time_burst"`
 	NetRateLimiterOpsMaxRate       int64    `toml:"net_rate_limiter_ops_max_rate"`
@@ -486,6 +490,34 @@ func (h hypervisor) getInitrdAndImage() (initrd string, image string, err error)
 	return
 }
 
+func (h hypervisor) getDiskRateLimiterBwMaxRate() int64 {
+	return h.DiskRateLimiterBwMaxRate
+}
+
+func (h hypervisor) getDiskRateLimiterBwOneTimeBurst() int64 {
+	if h.DiskRateLimiterBwOneTimeBurst != 0 && h.getDiskRateLimiterBwMaxRate() == 0 {
+		kataUtilsLogger.Warn("The DiskRateLimiterBwOneTimeBurst is set but DiskRateLimiterBwMaxRate is not set, this option will be ignored.")
+
+		h.DiskRateLimiterBwOneTimeBurst = 0
+	}
+
+	return h.DiskRateLimiterBwOneTimeBurst
+}
+
+func (h hypervisor) getDiskRateLimiterOpsMaxRate() int64 {
+	return h.DiskRateLimiterOpsMaxRate
+}
+
+func (h hypervisor) getDiskRateLimiterOpsOneTimeBurst() int64 {
+	if h.DiskRateLimiterOpsOneTimeBurst != 0 && h.getDiskRateLimiterOpsMaxRate() == 0 {
+		kataUtilsLogger.Warn("The DiskRateLimiterOpsOneTimeBurst is set but DiskRateLimiterOpsMaxRate is not set, this option will be ignored.")
+
+		h.DiskRateLimiterOpsOneTimeBurst = 0
+	}
+
+	return h.DiskRateLimiterOpsOneTimeBurst
+}
+
 func (h hypervisor) getRxRateLimiterCfg() uint64 {
 	return h.RxRateLimiterMaxRate
 }

src/runtime/virtcontainers/hypervisor.go

@@ -380,6 +380,24 @@ type HypervisorConfig struct {
 	// Enable SGX. Hardware-based isolation and memory encryption.
 	SGXEPCSize int64
 
+	// DiskRateLimiterBwRate is used to control disk I/O bandwidth on VM level.
+	// The same value, defined in bits per second, is used for inbound and outbound bandwidth.
+	DiskRateLimiterBwMaxRate int64
+
+	// DiskRateLimiterBwOneTimeBurst is used to control disk I/O bandwidth on VM level.
+	// This increases the initial max rate and this initial extra credit does *NOT* replenish
+	// and can be used for an *initial* burst of data.
+	DiskRateLimiterBwOneTimeBurst int64
+
+	// DiskRateLimiterOpsRate is used to control disk I/O operations on VM level.
+	// The same value, defined in operations per second, is used for inbound and outbound bandwidth.
+	DiskRateLimiterOpsMaxRate int64
+
+	// DiskRateLimiterOpsOneTimeBurst is used to control disk I/O operations on VM level.
+	// This increases the initial max rate and this initial extra credit does *NOT* replenish
+	// and can be used for an *initial* burst of data.
+	DiskRateLimiterOpsOneTimeBurst int64
+
 	// RxRateLimiterMaxRate is used to control network I/O inbound bandwidth on VM level.
 	RxRateLimiterMaxRate uint64