[PATCH v5 5/7] KVM: arm64: Always set HCR_TID2

From: Akihiko Odaki
Date: Fri Dec 30 2022 - 04:55:31 EST


Always set HCR_TID2 to trap CTR_EL0, CCSIDR2_EL1, CLIDR_EL1, and
CSSELR_EL1. This saves a few lines of code and allows to employ their
access trap handlers for more purposes anticipated by the old
condition for setting HCR_TID2.

Suggested-by: Marc Zyngier <maz@xxxxxxxxxx>
Signed-off-by: Akihiko Odaki <akihiko.odaki@xxxxxxxxxx>
---
arch/arm64/include/asm/kvm_arm.h | 3 ++-
arch/arm64/include/asm/kvm_emulate.h | 4 ----
arch/arm64/include/asm/kvm_host.h | 2 --
arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 2 --
4 files changed, 2 insertions(+), 9 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_arm.h b/arch/arm64/include/asm/kvm_arm.h
index 8aa8492dafc0..44be46c280c1 100644
--- a/arch/arm64/include/asm/kvm_arm.h
+++ b/arch/arm64/include/asm/kvm_arm.h
@@ -81,11 +81,12 @@
* SWIO: Turn set/way invalidates into set/way clean+invalidate
* PTW: Take a stage2 fault if a stage1 walk steps in device memory
* TID3: Trap EL1 reads of group 3 ID registers
+ * TID2: Trap CTR_EL0, CCSIDR2_EL1, CLIDR_EL1, and CSSELR_EL1
*/
#define HCR_GUEST_FLAGS (HCR_TSC | HCR_TSW | HCR_TWE | HCR_TWI | HCR_VM | \
HCR_BSU_IS | HCR_FB | HCR_TACR | \
HCR_AMO | HCR_SWIO | HCR_TIDCP | HCR_RW | HCR_TLOR | \
- HCR_FMO | HCR_IMO | HCR_PTW | HCR_TID3 )
+ HCR_FMO | HCR_IMO | HCR_PTW | HCR_TID3 | HCR_TID2)
#define HCR_VIRT_EXCP_MASK (HCR_VSE | HCR_VI | HCR_VF)
#define HCR_HOST_NVHE_FLAGS (HCR_RW | HCR_API | HCR_APK | HCR_ATA)
#define HCR_HOST_NVHE_PROTECTED_FLAGS (HCR_HOST_NVHE_FLAGS | HCR_TSC)
diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index 9bdba47f7e14..30c4598d643b 100644
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -88,10 +88,6 @@ static inline void vcpu_reset_hcr(struct kvm_vcpu *vcpu)
if (vcpu_el1_is_32bit(vcpu))
vcpu->arch.hcr_el2 &= ~HCR_RW;

- if (cpus_have_const_cap(ARM64_MISMATCHED_CACHE_TYPE) ||
- vcpu_el1_is_32bit(vcpu))
- vcpu->arch.hcr_el2 |= HCR_TID2;
-
if (kvm_has_mte(vcpu->kvm))
vcpu->arch.hcr_el2 |= HCR_ATA;
}
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 45e2136322ba..cc2ede0eaed4 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -621,7 +621,6 @@ static inline bool __vcpu_read_sys_reg_from_cpu(int reg, u64 *val)
return false;

switch (reg) {
- case CSSELR_EL1: *val = read_sysreg_s(SYS_CSSELR_EL1); break;
case SCTLR_EL1: *val = read_sysreg_s(SYS_SCTLR_EL12); break;
case CPACR_EL1: *val = read_sysreg_s(SYS_CPACR_EL12); break;
case TTBR0_EL1: *val = read_sysreg_s(SYS_TTBR0_EL12); break;
@@ -666,7 +665,6 @@ static inline bool __vcpu_write_sys_reg_to_cpu(u64 val, int reg)
return false;

switch (reg) {
- case CSSELR_EL1: write_sysreg_s(val, SYS_CSSELR_EL1); break;
case SCTLR_EL1: write_sysreg_s(val, SYS_SCTLR_EL12); break;
case CPACR_EL1: write_sysreg_s(val, SYS_CPACR_EL12); break;
case TTBR0_EL1: write_sysreg_s(val, SYS_TTBR0_EL12); break;
diff --git a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
index baa5b9b3dde5..147cb4c846c6 100644
--- a/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
+++ b/arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h
@@ -39,7 +39,6 @@ static inline bool ctxt_has_mte(struct kvm_cpu_context *ctxt)

static inline void __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
{
- ctxt_sys_reg(ctxt, CSSELR_EL1) = read_sysreg(csselr_el1);
ctxt_sys_reg(ctxt, SCTLR_EL1) = read_sysreg_el1(SYS_SCTLR);
ctxt_sys_reg(ctxt, CPACR_EL1) = read_sysreg_el1(SYS_CPACR);
ctxt_sys_reg(ctxt, TTBR0_EL1) = read_sysreg_el1(SYS_TTBR0);
@@ -95,7 +94,6 @@ static inline void __sysreg_restore_user_state(struct kvm_cpu_context *ctxt)
static inline void __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
{
write_sysreg(ctxt_sys_reg(ctxt, MPIDR_EL1), vmpidr_el2);
- write_sysreg(ctxt_sys_reg(ctxt, CSSELR_EL1), csselr_el1);

if (has_vhe() ||
!cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) {
--
2.38.1