From e342925f1777f73befda61b48845b0bc88a33181 Mon Sep 17 00:00:00 2001 From: James Hogan Date: Wed, 15 Jun 2016 19:30:00 +0100 Subject: [PATCH] MIPS: KVM: Report more accurate CP0_Config fields to guest MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Initialise the guest's CP0_Config register with a few more bits of information from the host. The BE bit should be set on big endian machines, the VI bit should be set on machines with a virtually tagged instruction cache, and the reported architecture revision should match that of the host (since we won't support emulating pre-r6 instruction encodings on r6 or vice versa). Signed-off-by: James Hogan Cc: Paolo Bonzini Cc: Radim Krčmář Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini --- arch/mips/kvm/trap_emul.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/arch/mips/kvm/trap_emul.c b/arch/mips/kvm/trap_emul.c index eb191c4612bb..1dc003ddca91 100644 --- a/arch/mips/kvm/trap_emul.c +++ b/arch/mips/kvm/trap_emul.c @@ -426,7 +426,7 @@ static int kvm_trap_emul_vcpu_init(struct kvm_vcpu *vcpu) static int kvm_trap_emul_vcpu_setup(struct kvm_vcpu *vcpu) { struct mips_coproc *cop0 = vcpu->arch.cop0; - u32 config1; + u32 config, config1; int vcpu_id = vcpu->vcpu_id; /* @@ -434,10 +434,20 @@ static int kvm_trap_emul_vcpu_setup(struct kvm_vcpu *vcpu) * guest will come up as expected, for now we simulate a MIPS 24kc */ kvm_write_c0_guest_prid(cop0, 0x00019300); - /* Have config1, Cacheable, noncoherent, write-back, write allocate */ - kvm_write_c0_guest_config(cop0, MIPS_CONF_M | (0x3 << CP0C0_K0) | - (0x1 << CP0C0_AR) | - (MMU_TYPE_R4000 << CP0C0_MT)); + /* + * Have config1, Cacheable, noncoherent, write-back, write allocate. + * Endianness, arch revision & virtually tagged icache should match + * host. + */ + config = read_c0_config() & MIPS_CONF_AR; + config |= MIPS_CONF_M | (0x3 << CP0C0_K0) | + (MMU_TYPE_R4000 << CP0C0_MT); +#ifdef CONFIG_CPU_BIG_ENDIAN + config |= CONF_BE; +#endif + if (cpu_has_vtag_icache) + config |= MIPS_CONF_VI; + kvm_write_c0_guest_config(cop0, config); /* Read the cache characteristics from the host Config1 Register */ config1 = (read_c0_config1() & ~0x7f); -- 2.20.1