Merge pull request #5177 from lubinszARM:pr_kernel_global

PiperOrigin-RevId: 350375461

3 files changed, 37 insertions, 24 deletions

diff --git a/pkg/sentry/platform/kvm/machine_arm64.go b/pkg/sentry/platform/kvm/machine_arm64.go
index 54837f20c..aa2d21748 100644
--- a/pkg/sentry/platform/kvm/machine_arm64.go
+++ b/pkg/sentry/platform/kvm/machine_arm64.go
@@ -54,7 +54,7 @@ func (m *machine) mapUpperHalf(pageTable *pagetables.PageTables) {
 		pageTable.Map(
 			usermem.Addr(ring0.KernelStartAddress|pr.virtual),
 			pr.length,
-			pagetables.MapOpts{AccessType: usermem.AnyAccess},
+			pagetables.MapOpts{AccessType: usermem.AnyAccess, Global: true},
 			pr.physical)
 
 		return true // Keep iterating.
diff --git a/pkg/sentry/platform/kvm/machine_arm64_unsafe.go b/pkg/sentry/platform/kvm/machine_arm64_unsafe.go
index 3f5be276b..67f7f88f2 100644
--- a/pkg/sentry/platform/kvm/machine_arm64_unsafe.go
+++ b/pkg/sentry/platform/kvm/machine_arm64_unsafe.go
@@ -79,7 +79,7 @@ func (c *vCPU) initArchState() error {
 	}
 
 	// tcr_el1
-	data = _TCR_TXSZ_VA48 | _TCR_CACHE_FLAGS | _TCR_SHARED | _TCR_TG_FLAGS | _TCR_ASID16 | _TCR_IPS_40BITS | _TCR_A1
+	data = _TCR_TXSZ_VA48 | _TCR_CACHE_FLAGS | _TCR_SHARED | _TCR_TG_FLAGS | _TCR_ASID16 | _TCR_IPS_40BITS
 	reg.id = _KVM_ARM64_REGS_TCR_EL1
 	if err := c.setOneRegister(&reg); err != nil {
 		return err
@@ -103,7 +103,7 @@ func (c *vCPU) initArchState() error {
 	c.SetTtbr0Kvm(uintptr(data))
 
 	// ttbr1_el1
-	data = c.machine.kernel.PageTables.TTBR1_EL1(false, 1)
+	data = c.machine.kernel.PageTables.TTBR1_EL1(false, 0)
 
 	reg.id = _KVM_ARM64_REGS_TTBR1_EL1
 	if err := c.setOneRegister(&reg); err != nil {
diff --git a/pkg/sentry/platform/ring0/entry_arm64.s b/pkg/sentry/platform/ring0/entry_arm64.s
index cf0bf3528..7529b3362 100644
--- a/pkg/sentry/platform/ring0/entry_arm64.s
+++ b/pkg/sentry/platform/ring0/entry_arm64.s
@@ -271,24 +271,20 @@
 	WORD $0xd538d092;   //MRS   TPIDR_EL1, R18
 
 // SWITCH_TO_APP_PAGETABLE sets a new pagetable for a container application.
-#define SWITCH_TO_APP_PAGETABLE(from) \
-	MRS TTBR1_EL1, R0; \
-	MOVD CPU_APP_ASID(from), R1; \
-	BFI $48, R1, $16, R0; \
-	MSR R0, TTBR1_EL1; \ // set the ASID in TTBR1_EL1 (since TCR.A1 is set)
-	ISB $15; \
-	MOVD CPU_TTBR0_APP(from), RSV_REG; \
-	MSR RSV_REG, TTBR0_EL1;
+#define SWITCH_TO_APP_PAGETABLE() \
+	MOVD CPU_APP_ASID(RSV_REG), RSV_REG_APP; \
+	MOVD CPU_TTBR0_APP(RSV_REG), RSV_REG; \
+	BFI $48, RSV_REG_APP, $16, RSV_REG; \
+	MSR RSV_REG, TTBR0_EL1; \
+	ISB $15;
 
 // SWITCH_TO_KVM_PAGETABLE sets the kvm pagetable.
-#define SWITCH_TO_KVM_PAGETABLE(from) \
-	MRS TTBR1_EL1, R0; \
-	MOVD $1, R1; \
-	BFI $48, R1, $16, R0; \
-	MSR R0, TTBR1_EL1; \
-	ISB $15; \
-	MOVD CPU_TTBR0_KVM(from), RSV_REG; \
-	MSR RSV_REG, TTBR0_EL1;
+#define SWITCH_TO_KVM_PAGETABLE() \
+	MOVD CPU_TTBR0_KVM(RSV_REG), RSV_REG; \
+	MOVD $1, RSV_REG_APP; \
+	BFI $48, RSV_REG_APP, $16, RSV_REG; \
+	MSR RSV_REG, TTBR0_EL1; \
+	ISB $15;
 
 TEXT ·EnableVFP(SB),NOSPLIT,$0
 	MOVD $FPEN_ENABLE, R0
@@ -496,7 +492,7 @@ do_exit_to_el0:
 
 	WORD $0xd538d092    //MRS   TPIDR_EL1, R18
 
-	SWITCH_TO_APP_PAGETABLE(RSV_REG)
+	SWITCH_TO_APP_PAGETABLE()
 
 	LDP 16*1(RSP), (R0, R1)
 	LDP 16*0(RSP), (RSV_REG, RSV_REG_APP)
@@ -521,10 +517,10 @@ TEXT ·kernelExitToEl1(SB),NOSPLIT,$0
 	MOVD CPU_REGISTERS+PTRACE_SP(RSV_REG), R1
 	MOVD R1, RSP
 
-	SWITCH_TO_KVM_PAGETABLE(RSV_REG)
+	REGISTERS_LOAD(RSV_REG, CPU_REGISTERS)
+	SWITCH_TO_KVM_PAGETABLE()
 	MRS TPIDR_EL1, RSV_REG
 
-	REGISTERS_LOAD(RSV_REG, CPU_REGISTERS)
 	MOVD CPU_REGISTERS+PTRACE_R9(RSV_REG), RSV_REG_APP
 
 	ERET()
@@ -532,8 +528,16 @@ TEXT ·kernelExitToEl1(SB),NOSPLIT,$0
 // Start is the CPU entrypoint.
 TEXT ·Start(SB),NOSPLIT,$0
 	// Init.
-	MOVD $SCTLR_EL1_DEFAULT, R1
-	MSR R1, SCTLR_EL1
+	WORD $0xd508871f    // __tlbi(vmalle1)
+	DSB $7          // dsb(nsh)
+
+	MOVD $1<<12, R1         // Reset mdscr_el1 and disable
+	MSR R1, MDSCR_EL1       // access to the DCC from EL0
+	ISB $15
+
+	MRS TTBR1_EL1, R1
+	MSR R1, TTBR0_EL1
+	ISB $15
 
 	MOVD $CNTKCTL_EL1_DEFAULT, R1
 	MSR R1, CNTKCTL_EL1
@@ -542,6 +546,15 @@ TEXT ·Start(SB),NOSPLIT,$0
 	ORR $0xffff000000000000, RSV_REG, RSV_REG
 	WORD $0xd518d092        //MSR R18, TPIDR_EL1
 
+	// Init.
+	MOVD $SCTLR_EL1_DEFAULT, R1 // re-enable the mmu.
+	MSR R1, SCTLR_EL1
+	ISB $15
+	WORD $0xd508751f // ic iallu
+
+	DSB $7          // dsb(nsh)
+	ISB $15
+
 	B ·kernelExitToEl1(SB)
 
 // El1_sync_invalid is the handler for an invalid EL1_sync.