aarch32 has pairs of registers to access the high and low parts of 64bit registers. KVM has a union of 64bit sys_regs[] and 32bit copro[]. The 32bit accessors read the high or low part of the 64bit sys_reg[] value through the union.
Both sys_reg_descs[] and cp15_regs[] list access_csselr() as the accessor for CSSELR{,_EL1}. access_csselr() is only aware of the 64bit sys_regs[], and expects r->reg to be 'CSSELR_EL1' in the enum, index 2 of the 64bit array.
cp15_regs[] uses the 32bit copro[] alias of sys_regs[]. Here CSSELR is c0_CSSELR which is the same location in sys_reg[]. r->reg is 'c0_CSSELR', index 4 in the 32bit array.
access_csselr() uses the 32bit r->reg value to access the 64bit array, so reads and write the wrong value. sys_regs[4], is ACTLR_EL1, which is subsequently save/restored when we enter the guest.
ACTLR_EL1 is supposed to be read-only for the guest. This register only affects execution at EL1, and the host's value is restored before we return to host EL1.
Rename access_csselr() to access_csselr_el1(), to indicate it expects the 64bit register index, and pass it CSSELR_EL1 from cp15_regs[].
Cc: stable@vger.kernel.org Signed-off-by: James Morse james.morse@arm.com ---- Providing access_csselr_cp15() wouldn't work as with VHE CSSELR_EL1 is loaded on the CPU while this code runs. access_csselr_cp15() would have to map it back the 64bit resgister to use vcpu_write_sys_reg(). We may as well do it in the table.
arch/arm64/kvm/sys_regs.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 51db934702b6..2eda539f3281 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -1302,7 +1302,7 @@ static bool access_clidr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, return true; }
-static bool access_csselr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, +static bool access_csselr_el1(struct kvm_vcpu *vcpu, struct sys_reg_params *p, const struct sys_reg_desc *r) { if (p->is_write) @@ -1566,7 +1566,7 @@ static const struct sys_reg_desc sys_reg_descs[] = {
{ SYS_DESC(SYS_CCSIDR_EL1), access_ccsidr }, { SYS_DESC(SYS_CLIDR_EL1), access_clidr }, - { SYS_DESC(SYS_CSSELR_EL1), access_csselr, reset_unknown, CSSELR_EL1 }, + { SYS_DESC(SYS_CSSELR_EL1), access_csselr_el1, reset_unknown, CSSELR_EL1 }, { SYS_DESC(SYS_CTR_EL0), access_ctr },
{ SYS_DESC(SYS_PMCR_EL0), access_pmcr, reset_pmcr, PMCR_EL0 }, @@ -2060,7 +2060,7 @@ static const struct sys_reg_desc cp15_regs[] = {
{ Op1(1), CRn( 0), CRm( 0), Op2(0), access_ccsidr }, { Op1(1), CRn( 0), CRm( 0), Op2(1), access_clidr }, - { Op1(2), CRn( 0), CRm( 0), Op2(0), access_csselr, NULL, c0_CSSELR }, + { Op1(2), CRn( 0), CRm( 0), Op2(0), access_csselr_el1, NULL, CSSELR_EL1 }, };
static const struct sys_reg_desc cp15_64_regs[] = {