Our current ID register filtering is starting to be a mess of if()
statements, and isn't going to get any saner.
Let's turn it into a switch(), which has a chance of being more
readable.
Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
---
arch/arm64/kvm/sys_regs.c | 22 +++++++++++++++-------
1 file changed, 15 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index da82c4b03aab..682fedd7700f 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -9,6 +9,7 @@
* Christoffer Dall <c.dall@xxxxxxxxxxxxxxxxxxxxxx>
*/
+#include <linux/bitfield.h>
#include <linux/bsearch.h>
#include <linux/kvm_host.h>
#include <linux/mm.h>
@@ -1070,6 +1071,8 @@ static bool access_arch_timer(struct kvm_vcpu *vcpu,
return true;
}
+#define FEATURE(x) (GENMASK_ULL(x##_SHIFT + 3, x##_SHIFT))
+
/* Read a sanitised cpufeature ID register by sys_reg_desc */
static u64 read_id_reg(const struct kvm_vcpu *vcpu,
struct sys_reg_desc const *r, bool raz)
@@ -1078,13 +1081,18 @@ static u64 read_id_reg(const struct kvm_vcpu *vcpu,
(u32)r->CRn, (u32)r->CRm, (u32)r->Op2);
u64 val = raz ? 0 : read_sanitised_ftr_reg(id);
- if (id == SYS_ID_AA64PFR0_EL1 && !vcpu_has_sve(vcpu)) {
- val &= ~(0xfUL << ID_AA64PFR0_SVE_SHIFT);
- } else if (id == SYS_ID_AA64ISAR1_EL1 && !vcpu_has_ptrauth(vcpu)) {
- val &= ~((0xfUL << ID_AA64ISAR1_APA_SHIFT) |
- (0xfUL << ID_AA64ISAR1_API_SHIFT) |
- (0xfUL << ID_AA64ISAR1_GPA_SHIFT) |
- (0xfUL << ID_AA64ISAR1_GPI_SHIFT));
+ switch (id) {
+ case SYS_ID_AA64PFR0_EL1:
+ if (!vcpu_has_sve(vcpu))
+ val &= ~FEATURE(ID_AA64PFR0_SVE);
+ break;
+ case SYS_ID_AA64ISAR1_EL1:
+ if (!vcpu_has_ptrauth(vcpu))
+ val &= ~(FEATURE(ID_AA64ISAR1_APA) |
+ FEATURE(ID_AA64ISAR1_API) |
+ FEATURE(ID_AA64ISAR1_GPA) |
+ FEATURE(ID_AA64ISAR1_GPI));
+ break;
}
return val;
--
2.20.1
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