[PATCH 1/3] KVM: arm64: Stash OSLSR_EL1 in the cpu context

Oliver Upton
2021-10-29T00:32:45Z

An upcoming change to KVM will context switch the OS Lock status between
guest/host. Add OSLSR_EL1 to the cpu context and handle guest reads
using the stored value.

Signed-off-by: Oliver Upton <oupton@google.com>
---
arch/arm64/include/asm/kvm_host.h | 1 +
arch/arm64/kvm/sys_regs.c | 13 ++++++-------
2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index f8be56d5342b..c98f65c4a1f7 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -172,6 +172,7 @@ enum vcpu_sysreg {
MDSCR_EL1, /* Monitor Debug System Control Register */
MDCCINT_EL1, /* Monitor Debug Comms Channel Interrupt Enable Reg */
DISR_EL1, /* Deferred Interrupt Status Register */
+ OSLSR_EL1, /* OS Lock Status Register */

/* Performance Monitors Registers */
PMCR_EL0, /* Control Register */
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 1d46e185f31e..0eb03e7508fe 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -291,12 +291,11 @@ static bool trap_oslsr_el1(struct kvm_vcpu *vcpu,
struct sys_reg_params *p,
const struct sys_reg_desc *r)
{
- if (p->is_write) {
+ if (p->is_write)
return ignore_write(vcpu, p);
- } else {
- p->regval = (1 << 3);
- return true;
- }
+
+ p->regval = vcpu_read_sys_reg(vcpu, r->reg);
+ return true;
}

static bool trap_dbgauthstatus_el1(struct kvm_vcpu *vcpu,
@@ -1441,7 +1440,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {

{ SYS_DESC(SYS_MDRAR_EL1), trap_raz_wi },
{ SYS_DESC(SYS_OSLAR_EL1), trap_raz_wi },
- { SYS_DESC(SYS_OSLSR_EL1), trap_oslsr_el1 },
+ { SYS_DESC(SYS_OSLSR_EL1), trap_oslsr_el1, reset_val, OSLSR_EL1, 0x00000008 },
{ SYS_DESC(SYS_OSDLR_EL1), trap_raz_wi },
{ SYS_DESC(SYS_DBGPRCR_EL1), trap_raz_wi },
{ SYS_DESC(SYS_DBGCLAIMSET_EL1), trap_raz_wi },
@@ -1916,7 +1915,7 @@ static const struct sys_reg_desc cp14_regs[] = {
{ Op1( 0), CRn( 1), CRm( 0), Op2( 4), trap_raz_wi },
DBGBXVR(1),
/* DBGOSLSR */
- { Op1( 0), CRn( 1), CRm( 1), Op2( 4), trap_oslsr_el1 },
+ { Op1( 0), CRn( 1), CRm( 1), Op2( 4), trap_oslsr_el1, NULL, OSLSR_EL1 },
DBGBXVR(2),
DBGBXVR(3),
/* DBGOSDLR */
--
2.33.0.1079.g6e70778dc9-goog