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authorJames Morse <james.morse@arm.com>2020-05-29 18:06:56 +0300
committerMarc Zyngier <maz@kernel.org>2020-06-09 11:07:58 +0300
commite8679fedd026eb3b4655af83829d9036e32c9b97 (patch)
tree23e284ad77500de7a398a9d1a5fb8c2d59b6cc34 /arch/arm64/kvm
parentef5a294be8d0e17b91d23be905f69368b0d3952e (diff)
downloadlinux-e8679fedd026eb3b4655af83829d9036e32c9b97.tar.xz
KVM: arm64: Stop save/restoring ACTLR_EL1
KVM sets HCR_EL2.TACR via HCR_GUEST_FLAGS. This means ACTLR* accesses from the guest are always trapped, and always return the value in the sys_regs array. The guest can't change the value of these registers, so we are save restoring the reset value, which came from the host. Stop save/restoring this register. Keep the storage for this register in sys_regs[] as this is how the value is exposed to user-space, removing it would break migration. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20200529150656.7339-4-james.morse@arm.com
Diffstat (limited to 'arch/arm64/kvm')
-rw-r--r--arch/arm64/kvm/hyp/sysreg-sr.c2
-rw-r--r--arch/arm64/kvm/sys_regs.c2
2 files changed, 0 insertions, 4 deletions
diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c
index 6d2df9fe0b5d..0d60e6ee96b2 100644
--- a/arch/arm64/kvm/hyp/sysreg-sr.c
+++ b/arch/arm64/kvm/hyp/sysreg-sr.c
@@ -39,7 +39,6 @@ static void __hyp_text __sysreg_save_el1_state(struct kvm_cpu_context *ctxt)
{
ctxt->sys_regs[CSSELR_EL1] = read_sysreg(csselr_el1);
ctxt->sys_regs[SCTLR_EL1] = read_sysreg_el1(SYS_SCTLR);
- ctxt->sys_regs[ACTLR_EL1] = read_sysreg(actlr_el1);
ctxt->sys_regs[CPACR_EL1] = read_sysreg_el1(SYS_CPACR);
ctxt->sys_regs[TTBR0_EL1] = read_sysreg_el1(SYS_TTBR0);
ctxt->sys_regs[TTBR1_EL1] = read_sysreg_el1(SYS_TTBR1);
@@ -122,7 +121,6 @@ static void __hyp_text __sysreg_restore_el1_state(struct kvm_cpu_context *ctxt)
isb();
}
- write_sysreg(ctxt->sys_regs[ACTLR_EL1], actlr_el1);
write_sysreg_el1(ctxt->sys_regs[CPACR_EL1], SYS_CPACR);
write_sysreg_el1(ctxt->sys_regs[TTBR0_EL1], SYS_TTBR0);
write_sysreg_el1(ctxt->sys_regs[TTBR1_EL1], SYS_TTBR1);
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 12f8d57a3cb8..dfb966f3863a 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -78,7 +78,6 @@ static bool __vcpu_read_sys_reg_from_cpu(int reg, u64 *val)
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 ACTLR_EL1: *val = read_sysreg_s(SYS_ACTLR_EL1); break;
case CPACR_EL1: *val = read_sysreg_s(SYS_CPACR_EL12); break;
case TTBR0_EL1: *val = read_sysreg_s(SYS_TTBR0_EL12); break;
case TTBR1_EL1: *val = read_sysreg_s(SYS_TTBR1_EL12); break;
@@ -118,7 +117,6 @@ static bool __vcpu_write_sys_reg_to_cpu(u64 val, int reg)
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 ACTLR_EL1: write_sysreg_s(val, SYS_ACTLR_EL1); break;
case CPACR_EL1: write_sysreg_s(val, SYS_CPACR_EL12); break;
case TTBR0_EL1: write_sysreg_s(val, SYS_TTBR0_EL12); break;
case TTBR1_EL1: write_sysreg_s(val, SYS_TTBR1_EL12); break;