diff options
| -rw-r--r-- | pkg/sentry/platform/ring0/pagetables/BUILD | 3 | ||||
| -rw-r--r-- | pkg/sentry/platform/ring0/pagetables/pcids.go | 5 | ||||
| -rw-r--r-- | pkg/sentry/platform/ring0/pagetables/pcids_aarch64.go | 32 | ||||
| -rw-r--r-- | pkg/sentry/platform/ring0/pagetables/pcids_aarch64.s | 45 | ||||
| -rw-r--r-- | pkg/sentry/platform/ring0/pagetables/pcids_x86.go | 20 |
5 files changed, 101 insertions, 4 deletions
diff --git a/pkg/sentry/platform/ring0/pagetables/BUILD b/pkg/sentry/platform/ring0/pagetables/BUILD index 581841555..16d5f478b 100644 --- a/pkg/sentry/platform/ring0/pagetables/BUILD +++ b/pkg/sentry/platform/ring0/pagetables/BUILD @@ -81,6 +81,9 @@ go_library( "pagetables_arm64.go", "pagetables_x86.go", "pcids.go", + "pcids_aarch64.go", + "pcids_aarch64.s", + "pcids_x86.go", "walker_amd64.go", "walker_arm64.go", "walker_empty.go", diff --git a/pkg/sentry/platform/ring0/pagetables/pcids.go b/pkg/sentry/platform/ring0/pagetables/pcids.go index 9206030bf..964496aac 100644 --- a/pkg/sentry/platform/ring0/pagetables/pcids.go +++ b/pkg/sentry/platform/ring0/pagetables/pcids.go @@ -18,9 +18,6 @@ import ( "gvisor.dev/gvisor/pkg/sync" ) -// limitPCID is the number of valid PCIDs. -const limitPCID = 4096 - // PCIDs is a simple PCID database. // // This is not protected by locks and is thus suitable for use only with a @@ -44,7 +41,7 @@ type PCIDs struct { // // Nil is returned iff the start and size are out of range. func NewPCIDs(start, size uint16) *PCIDs { - if start+uint16(size) >= limitPCID { + if start+uint16(size) > limitPCID { return nil // See comment. } p := &PCIDs{ diff --git a/pkg/sentry/platform/ring0/pagetables/pcids_aarch64.go b/pkg/sentry/platform/ring0/pagetables/pcids_aarch64.go new file mode 100644 index 000000000..fbfd41d83 --- /dev/null +++ b/pkg/sentry/platform/ring0/pagetables/pcids_aarch64.go @@ -0,0 +1,32 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// +build arm64 + +package pagetables + +// limitPCID is the maximum value of PCIDs. +// +// In VMSAv8-64, the PCID(ASID) size is an IMPLEMENTATION DEFINED choice +// of 8 bits or 16 bits, and ID_AA64MMFR0_EL1.ASIDBits identifies the +// supported size. When an implementation supports a 16-bit ASID, TCR_ELx.AS +// selects whether the top 8 bits of the ASID are used. +var limitPCID uint16 + +// GetASIDBits return the system ASID bits, 8 or 16 bits. +func GetASIDBits() uint8 + +func init() { + limitPCID = uint16(1)<<GetASIDBits() - 1 +} diff --git a/pkg/sentry/platform/ring0/pagetables/pcids_aarch64.s b/pkg/sentry/platform/ring0/pagetables/pcids_aarch64.s new file mode 100644 index 000000000..e9d62d768 --- /dev/null +++ b/pkg/sentry/platform/ring0/pagetables/pcids_aarch64.s @@ -0,0 +1,45 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// +build arm64 + +#include "funcdata.h" +#include "textflag.h" + +#define ID_AA64MMFR0_ASIDBITS_SHIFT 4 +#define ID_AA64MMFR0_ASIDBITS_16 2 +#define TCR_EL1_AS_BIT 36 + +// GetASIDBits return the system ASID bits, 8 or 16 bits. +// +// func GetASIDBits() uint8 +TEXT ·GetASIDBits(SB),NOSPLIT,$0-1 + // First, check whether 16bits ASID is supported. + // ID_AA64MMFR0_EL1.ASIDBITS[7:4] == 0010. + WORD $0xd5380700 // MRS ID_AA64MMFR0_EL1, R0 + UBFX $ID_AA64MMFR0_ASIDBITS_SHIFT, R0, $4, R0 + CMPW $ID_AA64MMFR0_ASIDBITS_16, R0 + BNE bits_8 + + // Second, check whether 16bits ASID is enabled. + // TCR_EL1.AS[36] == 1. + WORD $0xd5382040 // MRS TCR_EL1, R0 + TBZ $TCR_EL1_AS_BIT, R0, bits_8 + MOVD $16, R0 + B done +bits_8: + MOVD $8, R0 +done: + MOVB R0, ret+0(FP) + RET diff --git a/pkg/sentry/platform/ring0/pagetables/pcids_x86.go b/pkg/sentry/platform/ring0/pagetables/pcids_x86.go new file mode 100644 index 000000000..91fc5e8dd --- /dev/null +++ b/pkg/sentry/platform/ring0/pagetables/pcids_x86.go @@ -0,0 +1,20 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// +build i386 amd64 + +package pagetables + +// limitPCID is the maximum value of valid PCIDs. +const limitPCID = 4095 |