add annotations to forbid small backing pages

Signed-off-by: Maksim An <maksiman@microsoft.com>
anmaxvl · Mar 20, 2024 · 5e9f54b · 5e9f54b
1 parent 6be41bc
commit 5e9f54b
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Showing 6 changed files with 32 additions and 19 deletions.
diff --git a/internal/hcs/schema2/memory_2.go b/internal/hcs/schema2/memory_2.go
@@ -28,6 +28,11 @@ type Memory2 struct {
 	// the guest operating system).
 	EnableColdDiscardHint bool `json:"EnableColdDiscardHint,omitempty"`
 
+	// ForbidSmallBackingPages if enabled, then backing page chunks smaller than the backing page
+	// size are never used unless the system is under extreme memory pressure. If the backing page
+	// is `Small`, then it is forced to `Large` when this option is enabled.
+	ForbidSmallBackingPages bool `json:"ForbidSmallBackingPages,omitempty"`
+
 	// LowMmioGapInMB is the low MMIO region allocated below 4GB.
 	//
 	// TODO: This is pre-release support in schema 2.3. Need to add build number

diff --git a/internal/oci/uvm.go b/internal/oci/uvm.go
@@ -245,6 +245,7 @@ func specToUVMCreateOptionsCommon(ctx context.Context, opts *uvm.Options, s *spe
 	opts.ProcessDumpLocation = ParseAnnotationsString(s.Annotations, annotations.ContainerProcessDumpLocation, opts.ProcessDumpLocation)
 	opts.NoWritableFileShares = ParseAnnotationsBool(ctx, s.Annotations, annotations.DisableWritableFileShares, opts.NoWritableFileShares)
 	opts.DumpDirectoryPath = ParseAnnotationsString(s.Annotations, annotations.DumpDirectoryPath, opts.DumpDirectoryPath)
+	opts.ForbidSmallBackingPages = ParseAnnotationsBool(ctx, s.Annotations, annotations.MemoryForbidSmallBackingPages, opts.ForbidSmallBackingPages)
 	maps.Copy(opts.AdditionalHyperVConfig, parseHVSocketServiceTable(ctx, s.Annotations))
 }
 

diff --git a/internal/uvm/create.go b/internal/uvm/create.go
@@ -49,6 +49,8 @@ type Options struct {
 	// commit, set to true.
 	EnableDeferredCommit bool
 
+	ForbidSmallBackingPages bool
+
 	// ProcessorCount sets the number of vCPU's. If `0` will default to platform
 	// default.
 	ProcessorCount int32

diff --git a/internal/uvm/create_lcow.go b/internal/uvm/create_lcow.go
@@ -413,13 +413,14 @@ func makeLCOWVMGSDoc(ctx context.Context, opts *OptionsLCOW, uvm *UtilityVM) (_
 			Chipset:     &hcsschema.Chipset{},
 			ComputeTopology: &hcsschema.Topology{
 				Memory: &hcsschema.Memory2{
-					SizeInMB:              memorySizeInMB,
-					AllowOvercommit:       opts.AllowOvercommit,
-					EnableDeferredCommit:  opts.EnableDeferredCommit,
-					EnableColdDiscardHint: opts.EnableColdDiscardHint,
-					LowMMIOGapInMB:        opts.LowMMIOGapInMB,
-					HighMMIOBaseInMB:      opts.HighMMIOBaseInMB,
-					HighMMIOGapInMB:       opts.HighMMIOGapInMB,
+					SizeInMB:                memorySizeInMB,
+					AllowOvercommit:         opts.AllowOvercommit,
+					EnableDeferredCommit:    opts.EnableDeferredCommit,
+					EnableColdDiscardHint:   opts.EnableColdDiscardHint,
+					LowMMIOGapInMB:          opts.LowMMIOGapInMB,
+					HighMMIOBaseInMB:        opts.HighMMIOBaseInMB,
+					HighMMIOGapInMB:         opts.HighMMIOGapInMB,
+					ForbidSmallBackingPages: opts.ForbidSmallBackingPages,
 				},
 				Processor: processor,
 			},
@@ -625,13 +626,14 @@ func makeLCOWDoc(ctx context.Context, opts *OptionsLCOW, uvm *UtilityVM) (_ *hcs
 			Chipset:     &hcsschema.Chipset{},
 			ComputeTopology: &hcsschema.Topology{
 				Memory: &hcsschema.Memory2{
-					SizeInMB:              memorySizeInMB,
-					AllowOvercommit:       opts.AllowOvercommit,
-					EnableDeferredCommit:  opts.EnableDeferredCommit,
-					EnableColdDiscardHint: opts.EnableColdDiscardHint,
-					LowMMIOGapInMB:        opts.LowMMIOGapInMB,
-					HighMMIOBaseInMB:      opts.HighMMIOBaseInMB,
-					HighMMIOGapInMB:       opts.HighMMIOGapInMB,
+					SizeInMB:                memorySizeInMB,
+					AllowOvercommit:         opts.AllowOvercommit,
+					EnableDeferredCommit:    opts.EnableDeferredCommit,
+					EnableColdDiscardHint:   opts.EnableColdDiscardHint,
+					LowMMIOGapInMB:          opts.LowMMIOGapInMB,
+					HighMMIOBaseInMB:        opts.HighMMIOBaseInMB,
+					HighMMIOGapInMB:         opts.HighMMIOGapInMB,
+					ForbidSmallBackingPages: opts.ForbidSmallBackingPages,
 				},
 				Processor: processor,
 			},

diff --git a/internal/uvm/create_wcow.go b/internal/uvm/create_wcow.go
@@ -186,11 +186,12 @@ func prepareConfigDoc(ctx context.Context, uvm *UtilityVM, opts *OptionsWCOW, uv
 					SizeInMB:        memorySizeInMB,
 					AllowOvercommit: opts.AllowOvercommit,
 					// EnableHotHint is not compatible with physical.
-					EnableHotHint:        opts.AllowOvercommit,
-					EnableDeferredCommit: opts.EnableDeferredCommit,
-					LowMMIOGapInMB:       opts.LowMMIOGapInMB,
-					HighMMIOBaseInMB:     opts.HighMMIOBaseInMB,
-					HighMMIOGapInMB:      opts.HighMMIOGapInMB,
+					EnableHotHint:           opts.AllowOvercommit,
+					EnableDeferredCommit:    opts.EnableDeferredCommit,
+					LowMMIOGapInMB:          opts.LowMMIOGapInMB,
+					HighMMIOBaseInMB:        opts.HighMMIOBaseInMB,
+					HighMMIOGapInMB:         opts.HighMMIOGapInMB,
+					ForbidSmallBackingPages: opts.ForbidSmallBackingPages,
 				},
 				Processor: processor,
 			},

diff --git a/pkg/annotations/annotations.go b/pkg/annotations/annotations.go
@@ -130,6 +130,8 @@ const (
 	// MemoryHighMMIOGapInMB indicates the high MMIO gap in MB.
 	MemoryHighMMIOGapInMB = "io.microsoft.virtualmachine.computetopology.memory.highmmiogapinmb"
 
+	MemoryForbidSmallBackingPages = "io.microsoft.virtualmachine.computetopology.memory.forbidsmallbackingpages"
+
 	// ProcessorCount overrides the hypervisor isolated vCPU count set
 	// via the OCI spec.
 	//