On 2020-08-13 07:05, Peng Liang wrote:
To emulate the ID registers, we need a place to storage the values of
the ID regsiters. Maybe putting in kvm_arch_vcpu is a good idea.
This commit has no functional changes but only code refactor. When
initializing a vcpu, get the values of the ID registers from
arm64_ftr_regs and storage them in kvm_arch_vcpu. And we just read
the value from kvm_arch_vcpu when getting/setting the value of the ID
regs.
Signed-off-by: zhanghailiang <zhang.zhanghailiang@xxxxxxxxxx>
Signed-off-by: Peng Liang <liangpeng10@xxxxxxxxxx>
---
arch/arm64/include/asm/kvm_host.h | 2 ++
arch/arm64/kvm/arm.c | 20 ++++++++++++++++++++
arch/arm64/kvm/sys_regs.c | 27 +++++++++++++++++++++++----
include/uapi/linux/kvm.h | 11 +++++++++++
4 files changed, 56 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h
b/arch/arm64/include/asm/kvm_host.h
index f81151ad3d3c..7f7bd36702f7 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -336,6 +336,8 @@ struct kvm_vcpu_arch {
u64 last_steal;
gpa_t base;
} steal;
+
+ struct id_registers idregs;
System registers are to be stored in the sysreg file. I've already
spent enough time moving them out of the various subsystems.
};
/* Pointer to the vcpu's SVE FFR for sve_{save,load}_state() */
diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c
index 73e12869afe3..18ebbe1c64ee 100644
--- a/arch/arm64/kvm/arm.c
+++ b/arch/arm64/kvm/arm.c
@@ -262,6 +262,24 @@ int kvm_arch_vcpu_precreate(struct kvm *kvm,
unsigned int id)
return 0;
}
+static int get_cpu_ftr(u32 id, u64 val, void *argp)
+{
+ struct id_registers *idregs = argp;
+
+ /*
+ * (Op0, Op1, CRn, CRm, Op2) of ID registers is (3, 0, 0, crm, op2),
+ * where 1<=crm<8, 0<=op2<8.
+ */
+ if (sys_reg_Op0(id) == 3 && sys_reg_Op1(id) == 0 &&
+ sys_reg_CRn(id) == 0 && sys_reg_CRm(id) > 0) {
+ idregs->regs[idregs->num].sys_id = id;
+ idregs->regs[idregs->num].sys_val = val;
+ idregs->num++;
+ }
+
+ return 0;
+}
+
int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
{
int err;
@@ -285,6 +303,8 @@ int kvm_arch_vcpu_create(struct kvm_vcpu *vcpu)
if (err)
return err;
+ arm64_cpu_ftr_regs_traverse(get_cpu_ftr, &vcpu->arch.idregs);
+
return create_hyp_mappings(vcpu, vcpu + 1, PAGE_HYP);
}
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 138961d7ebe3..776c2757a01e 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1092,13 +1092,32 @@ static bool access_arch_timer(struct kvm_vcpu
*vcpu,
return true;
}
+static struct id_reg_info *kvm_id_reg(struct kvm_vcpu *vcpu, u64 id)
+{
+ int i;
+
+ for (i = 0; i < vcpu->arch.idregs.num; ++i) {
+ if (vcpu->arch.idregs.regs[i].sys_id == id)
+ return &vcpu->arch.idregs.regs[i];
+ }
+ return NULL;
+}
+
+static u64 kvm_get_id_reg(struct kvm_vcpu *vcpu, u64 id)
+{
+ struct id_reg_info *ri = kvm_id_reg(vcpu, id);
+
+ BUG_ON(!ri);
+ return ri->sys_val;
+}
+
/* Read a sanitised cpufeature ID register by sys_reg_desc */
-static u64 read_id_reg(const struct kvm_vcpu *vcpu,
+static u64 read_id_reg(struct kvm_vcpu *vcpu,
struct sys_reg_desc const *r, bool raz)
{
u32 id = sys_reg((u32)r->Op0, (u32)r->Op1,
(u32)r->CRn, (u32)r->CRm, (u32)r->Op2);
- u64 val = raz ? 0 : read_sanitised_ftr_reg(id);
+ u64 val = raz ? 0 : kvm_get_id_reg(vcpu, id);
if (id == SYS_ID_AA64PFR0_EL1) {
if (!vcpu_has_sve(vcpu))
@@ -1238,7 +1257,7 @@ static int set_id_aa64zfr0_el1(struct kvm_vcpu
*vcpu,
* are stored, and for set_id_reg() we don't allow the effective value
* to be changed.
*/
-static int __get_id_reg(const struct kvm_vcpu *vcpu,
+static int __get_id_reg(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd, void __user *uaddr,
bool raz)
{
@@ -1248,7 +1267,7 @@ static int __get_id_reg(const struct kvm_vcpu
*vcpu,
return reg_to_user(uaddr, &val, id);
}
-static int __set_id_reg(const struct kvm_vcpu *vcpu,
+static int __set_id_reg(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd, void __user *uaddr,
bool raz)
{
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index f6d86033c4fa..1029444d04aa 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1272,6 +1272,17 @@ struct kvm_vfio_spapr_tce {
__s32 tablefd;
};
+#define ID_REG_MAX_NUMS 64
+struct id_reg_info {
+ uint64_t sys_id;
+ uint64_t sys_val;
+};
+
+struct id_registers {
+ struct id_reg_info regs[ID_REG_MAX_NUMS];
+ uint64_t num;
+};
+
/*
* ioctls for VM fds
*/
No way this is an acceptable interface. We have the one-reg interface,
which takes a system register encoding.
M.
--
Jazz is not dead. It just smells funny...
