From ea1bdbf683e6a12bd60204d245053bca0b52185c Mon Sep 17 00:00:00 2001 From: James Hogan Date: Tue, 14 Mar 2017 10:15:30 +0000 Subject: [PATCH] KVM: MIPS: Update exit handler for VZ MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The general guest exit handler needs a few tweaks for VZ compared to trap & emulate, which for now are made directly depending on CONFIG_KVM_MIPS_VZ: - There is no need to re-enable the hardware page table walker (HTW), as it can be left enabled during guest mode operation with VZ. - There is no need to perform a privilege check, as any guest privilege violations should have already been detected by the hardware and triggered the appropriate guest exception. Signed-off-by: James Hogan Cc: Paolo Bonzini Cc: "Radim Krčmář" Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org --- arch/mips/kvm/mips.c | 31 ++++++++++++++++++------------- 1 file changed, 18 insertions(+), 13 deletions(-) diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c index 1fa088854cb6..8c10148a345c 100644 --- a/arch/mips/kvm/mips.c +++ b/arch/mips/kvm/mips.c @@ -1230,7 +1230,8 @@ int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu) vcpu->mode = OUTSIDE_GUEST_MODE; /* re-enable HTW before enabling interrupts */ - htw_start(); + if (!IS_ENABLED(CONFIG_KVM_MIPS_VZ)) + htw_start(); /* Set a default exit reason */ run->exit_reason = KVM_EXIT_UNKNOWN; @@ -1248,17 +1249,20 @@ int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu) cause, opc, run, vcpu); trace_kvm_exit(vcpu, exccode); - /* - * Do a privilege check, if in UM most of these exit conditions end up - * causing an exception to be delivered to the Guest Kernel - */ - er = kvm_mips_check_privilege(cause, opc, run, vcpu); - if (er == EMULATE_PRIV_FAIL) { - goto skip_emul; - } else if (er == EMULATE_FAIL) { - run->exit_reason = KVM_EXIT_INTERNAL_ERROR; - ret = RESUME_HOST; - goto skip_emul; + if (!IS_ENABLED(CONFIG_KVM_MIPS_VZ)) { + /* + * Do a privilege check, if in UM most of these exit conditions + * end up causing an exception to be delivered to the Guest + * Kernel + */ + er = kvm_mips_check_privilege(cause, opc, run, vcpu); + if (er == EMULATE_PRIV_FAIL) { + goto skip_emul; + } else if (er == EMULATE_FAIL) { + run->exit_reason = KVM_EXIT_INTERNAL_ERROR; + ret = RESUME_HOST; + goto skip_emul; + } } switch (exccode) { @@ -1418,7 +1422,8 @@ skip_emul: } /* Disable HTW before returning to guest or host */ - htw_stop(); + if (!IS_ENABLED(CONFIG_KVM_MIPS_VZ)) + htw_stop(); return ret; } -- 2.20.1