KVM: arm/arm64: Introduce vcpu_el1_is_32bit

We have numerous checks around that checks if the HCR_EL2 has the RW bit
set to figure out if we're running an AArch64 or AArch32 VM.  In some
cases, directly checking the RW bit (given its unintuitive name), is a
bit confusing, and that's not going to improve as we move logic around
for the following patches that optimize KVM on AArch64 hosts with VHE.

Therefore, introduce a helper, vcpu_el1_is_32bit, and replace existing
direct checks of HCR_EL2.RW with the helper.

Reviewed-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h
index 9ee316b962c8d555533562e3ef060421f9d2b619..3cc535591bdf9b59eea588f26dc4909040823357 100644 (file)
--- a/arch/arm64/include/asm/kvm_emulate.h
+++ b/arch/arm64/include/asm/kvm_emulate.h
@@ -45,6 +45,11 @@ void kvm_inject_undef32(struct kvm_vcpu *vcpu);
 void kvm_inject_dabt32(struct kvm_vcpu *vcpu, unsigned long addr);
 void kvm_inject_pabt32(struct kvm_vcpu *vcpu, unsigned long addr);
 
+static inline bool vcpu_el1_is_32bit(struct kvm_vcpu *vcpu)
+{
+       return !(vcpu->arch.hcr_el2 & HCR_RW);
+}
+
 static inline void vcpu_reset_hcr(struct kvm_vcpu *vcpu)
 {
        vcpu->arch.hcr_el2 = HCR_GUEST_FLAGS;
@@ -65,7 +70,7 @@ static inline void vcpu_reset_hcr(struct kvm_vcpu *vcpu)
         * For now this is conditional, since no AArch32 feature regs
         * are currently virtualised.
         */
-       if (vcpu->arch.hcr_el2 & HCR_RW)
+       if (!vcpu_el1_is_32bit(vcpu))
                vcpu->arch.hcr_el2 |= HCR_TID3;
 }
 

diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 80bf38ccc8a4ba21437dc6ec5701784f670d5556..c3e88ba81e26932305f83a3a2b31a0b8d5f9d8d2 100644 (file)
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -74,7 +74,7 @@ static hyp_alternate_select(__activate_traps_arch,
 
 static void __hyp_text __activate_traps(struct kvm_vcpu *vcpu)
 {
-       u64 val;
+       u64 hcr = vcpu->arch.hcr_el2;
 
        /*
         * We are about to set CPTR_EL2.TFP to trap all floating point
@@ -85,17 +85,16 @@ static void __hyp_text __activate_traps(struct kvm_vcpu *vcpu)
         * If FP/ASIMD is not implemented, FPEXC is UNDEFINED and any access to
         * it will cause an exception.
         */
-       val = vcpu->arch.hcr_el2;
-
-       if (!(val & HCR_RW) && system_supports_fpsimd()) {
+       if (vcpu_el1_is_32bit(vcpu) && system_supports_fpsimd()) {
                write_sysreg(1 << 30, fpexc32_el2);
                isb();
        }
-       write_sysreg(val, hcr_el2);
 
-       if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN) && (val & HCR_VSE))
+       if (cpus_have_const_cap(ARM64_HAS_RAS_EXTN) && (hcr & HCR_VSE))
                write_sysreg_s(vcpu->arch.vsesr_el2, SYS_VSESR_EL2);
 
+       write_sysreg(hcr, hcr_el2);
+
        /* Trap on AArch32 cp15 c15 accesses (EL1 or EL0) */
        write_sysreg(1 << 15, hstr_el2);
        /*

diff --git a/arch/arm64/kvm/hyp/sysreg-sr.c b/arch/arm64/kvm/hyp/sysreg-sr.c
index 434f0fc9cfb359f851941cda1ac535aabc5cdca4..99fc60516103eb552fdc576b37333f8846f4ad03 100644 (file)
--- a/arch/arm64/kvm/hyp/sysreg-sr.c
+++ b/arch/arm64/kvm/hyp/sysreg-sr.c
@@ -19,6 +19,7 @@
 #include <linux/kvm_host.h>
 
 #include <asm/kvm_asm.h>
+#include <asm/kvm_emulate.h>
 #include <asm/kvm_hyp.h>
 
 /* Yes, this does nothing, on purpose */
@@ -147,7 +148,7 @@ void __hyp_text __sysreg32_save_state(struct kvm_vcpu *vcpu)
 {
        u64 *spsr, *sysreg;
 
-       if (read_sysreg(hcr_el2) & HCR_RW)
+       if (!vcpu_el1_is_32bit(vcpu))
                return;
 
        spsr = vcpu->arch.ctxt.gp_regs.spsr;
@@ -172,7 +173,7 @@ void __hyp_text __sysreg32_restore_state(struct kvm_vcpu *vcpu)
 {
        u64 *spsr, *sysreg;
 
-       if (read_sysreg(hcr_el2) & HCR_RW)
+       if (!vcpu_el1_is_32bit(vcpu))
                return;
 
        spsr = vcpu->arch.ctxt.gp_regs.spsr;

diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c
index c1e179d34e6a844a8e601fcc9699584b46bac4ff..30a3f58cdb7bb19b2ee1b0fb031f8afcb52f2838 100644 (file)
--- a/arch/arm64/kvm/inject_fault.c
+++ b/arch/arm64/kvm/inject_fault.c
@@ -128,7 +128,7 @@ static void inject_undef64(struct kvm_vcpu *vcpu)
  */
 void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr)
 {
-       if (!(vcpu->arch.hcr_el2 & HCR_RW))
+       if (vcpu_el1_is_32bit(vcpu))
                kvm_inject_dabt32(vcpu, addr);
        else
                inject_abt64(vcpu, false, addr);
@@ -144,7 +144,7 @@ void kvm_inject_dabt(struct kvm_vcpu *vcpu, unsigned long addr)
  */
 void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr)
 {
-       if (!(vcpu->arch.hcr_el2 & HCR_RW))
+       if (vcpu_el1_is_32bit(vcpu))
                kvm_inject_pabt32(vcpu, addr);
        else
                inject_abt64(vcpu, true, addr);
@@ -158,7 +158,7 @@ void kvm_inject_pabt(struct kvm_vcpu *vcpu, unsigned long addr)
  */
 void kvm_inject_undefined(struct kvm_vcpu *vcpu)
 {
-       if (!(vcpu->arch.hcr_el2 & HCR_RW))
+       if (vcpu_el1_is_32bit(vcpu))
                kvm_inject_undef32(vcpu);
        else
                inject_undef64(vcpu);