In order to be able to propagate the pointer to the sys_reg descriptor
being currently emulated without having to rewrite a lot of the sys_reg
handling, let's allow the vcpu structure to have a pointer to the
current sys_reg_params.
The pointer is set in a helper function that calls the trap handler,
and reset just after.
Signed-off-by: Marc Zyngier <marc.zyng...@arm.com>
---
arch/arm64/include/asm/kvm_host.h | 5 +++++
arch/arm64/kvm/sys_regs.c | 40 +++++++++++++++++++++------------------
2 files changed, 27 insertions(+), 18 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h
b/arch/arm64/include/asm/kvm_host.h
index 4a758cba1262..9dfce56de9c0 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -194,6 +194,8 @@ struct kvm_cpu_context {
typedef struct kvm_cpu_context kvm_cpu_context_t;
+struct sys_reg_params;
+
struct kvm_vcpu_arch {
struct kvm_cpu_context ctxt;
@@ -270,6 +272,9 @@ struct kvm_vcpu_arch {
/* Detect first run of a vcpu */
bool has_run_once;
+
+ /* system register emulation in progress */
+ struct sys_reg_params *sys_reg;
};
#define vcpu_gp_regs(v) (&(v)->arch.ctxt.gp_regs)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 7ac7fb021dde..33bad02c0a00 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1557,6 +1557,26 @@ int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu,
struct kvm_run *run)
return 1;
}
+static bool perform_access(struct kvm_vcpu *vcpu,
+ struct sys_reg_params *params,
+ const struct sys_reg_desc *r)
+{
+ bool res;
+
+ /*
+ * Not having an accessor means that we have configured a trap
+ * that we don't know how to handle. This certainly qualifies
+ * as a gross bug that should be fixed right away.
+ */
+ BUG_ON(!r->access);
+
+ vcpu->arch.sys_reg = params;
+ res = r->access(vcpu, params, r);
+ vcpu->arch.sys_reg = NULL;
+
+ return res;
+}
+
/*
* emulate_cp -- tries to match a sys_reg access in a handling table, and
* call the corresponding trap handler.
@@ -1580,15 +1600,7 @@ static int emulate_cp(struct kvm_vcpu *vcpu,
r = find_reg(params, table, num);
if (r) {
- /*
- * Not having an accessor means that we have
- * configured a trap that we don't know how to
- * handle. This certainly qualifies as a gross bug
- * that should be fixed right away.
- */
- BUG_ON(!r->access);
-
- if (likely(r->access(vcpu, params, r))) {
+ if (likely(perform_access(vcpu, params, r))) {
/* Skip instruction, since it was emulated */
if (!params->exception_pending)
kvm_skip_instr(vcpu,
kvm_vcpu_trap_il_is32bit(vcpu));
@@ -1766,15 +1778,7 @@ static int emulate_sys_reg(struct kvm_vcpu *vcpu,
r = find_reg(params, sys_reg_descs, ARRAY_SIZE(sys_reg_descs));
if (likely(r)) {
- /*
- * Not having an accessor means that we have
- * configured a trap that we don't know how to
- * handle. This certainly qualifies as a gross bug
- * that should be fixed right away.
- */
- BUG_ON(!r->access);
-
- if (likely(r->access(vcpu, params, r))) {
+ if (likely(perform_access(vcpu, params, r))) {
/* Skip instruction, since it was emulated */
if (!params->exception_pending)
kvm_skip_instr(vcpu,
kvm_vcpu_trap_il_is32bit(vcpu));
--
2.11.0
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