From cc33c4e20185a391766ed5e78e2acc97e17ba511 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Tue, 13 Feb 2018 13:39:23 +0000 Subject: arm64/kvm: Prohibit guest LOR accesses We don't currently limit guest accesses to the LOR registers, which we neither virtualize nor context-switch. As such, guests are provided with unusable information/controls, and are not isolated from each other (or the host). To prevent these issues, we can trap register accesses and present the illusion LORegions are unssupported by the CPU. To do this, we mask ID_AA64MMFR1.LO, and set HCR_EL2.TLOR to trap accesses to the following registers: * LORC_EL1 * LOREA_EL1 * LORID_EL1 * LORN_EL1 * LORSA_EL1 ... when trapped, we inject an UNDEFINED exception to EL1, simulating their non-existence. As noted in D7.2.67, when no LORegions are implemented, LoadLOAcquire and StoreLORelease must behave as LoadAcquire and StoreRelease respectively. We can ensure this by clearing LORC_EL1.EN when a CPU's EL2 is first initialized, as the host kernel will not modify this. Signed-off-by: Mark Rutland Cc: Vladimir Murzin Cc: Catalin Marinas Cc: Christoffer Dall Cc: Marc Zyngier Cc: Will Deacon Cc: kvmarm@lists.cs.columbia.edu Signed-off-by: Christoffer Dall --- arch/arm64/include/asm/kvm_arm.h | 4 +++- arch/arm64/include/asm/sysreg.h | 6 ++++++ 2 files changed, 9 insertions(+), 1 deletion(-) (limited to 'arch/arm64/include') diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h index b0c84171e6a3..1b438c334463 100644 --- a/arch/arm64/include/asm/kvm_arm.h +++ b/arch/arm64/include/asm/kvm_arm.h @@ -25,6 +25,7 @@ /* Hyp Configuration Register (HCR) bits */ #define HCR_TEA (UL(1) << 37) #define HCR_TERR (UL(1) << 36) +#define HCR_TLOR (UL(1) << 35) #define HCR_E2H (UL(1) << 34) #define HCR_ID (UL(1) << 33) #define HCR_CD (UL(1) << 32) @@ -64,6 +65,7 @@ /* * The bits we set in HCR: + * TLOR: Trap LORegion register accesses * RW: 64bit by default, can be overridden for 32bit VMs * TAC: Trap ACTLR * TSC: Trap SMC @@ -81,7 +83,7 @@ */ #define HCR_GUEST_FLAGS (HCR_TSC | HCR_TSW | HCR_TWE | HCR_TWI | HCR_VM | \ HCR_TVM | HCR_BSU_IS | HCR_FB | HCR_TAC | \ - HCR_AMO | HCR_SWIO | HCR_TIDCP | HCR_RW) + HCR_AMO | HCR_SWIO | HCR_TIDCP | HCR_RW | HCR_TLOR) #define HCR_VIRT_EXCP_MASK (HCR_VSE | HCR_VI | HCR_VF) #define HCR_INT_OVERRIDE (HCR_FMO | HCR_IMO) #define HCR_HOST_VHE_FLAGS (HCR_RW | HCR_TGE | HCR_E2H) diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 0e1960c59197..69a99856461c 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -288,6 +288,12 @@ #define SYS_MAIR_EL1 sys_reg(3, 0, 10, 2, 0) #define SYS_AMAIR_EL1 sys_reg(3, 0, 10, 3, 0) +#define SYS_LORSA_EL1 sys_reg(3, 0, 10, 4, 0) +#define SYS_LOREA_EL1 sys_reg(3, 0, 10, 4, 1) +#define SYS_LORN_EL1 sys_reg(3, 0, 10, 4, 2) +#define SYS_LORC_EL1 sys_reg(3, 0, 10, 4, 3) +#define SYS_LORID_EL1 sys_reg(3, 0, 10, 4, 7) + #define SYS_VBAR_EL1 sys_reg(3, 0, 12, 0, 0) #define SYS_DISR_EL1 sys_reg(3, 0, 12, 1, 1) -- cgit v1.2.3