From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Hogan Subject: Re: [PATCH 05/21] MIPS: KVM: Add CP0_EPC KVM register access Date: Fri, 25 Apr 2014 21:29:18 +0100 Message-ID: <10468933.5AvfRZXSN7@radagast> References: <1398439204-26171-1-git-send-email-james.hogan@imgtec.com> <1398439204-26171-6-git-send-email-james.hogan@imgtec.com> <535A90E1.2030705@gmail.com> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="nextPart2325235.4a0bX7vO2r"; micalg="pgp-sha1"; protocol="application/pgp-signature" Cc: David Daney , Paolo Bonzini , Gleb Natapov , kvm@vger.kernel.org, Ralf Baechle , David Daney , Sanjay Lal To: linux-mips@linux-mips.org Return-path: Received: from mail-wg0-f52.google.com ([74.125.82.52]:53918 "EHLO mail-wg0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753336AbaDYU33 (ORCPT ); Fri, 25 Apr 2014 16:29:29 -0400 Received: by mail-wg0-f52.google.com with SMTP id b13so2921083wgh.35 for ; Fri, 25 Apr 2014 13:29:28 -0700 (PDT) In-Reply-To: <535A90E1.2030705@gmail.com> Sender: kvm-owner@vger.kernel.org List-ID: --nextPart2325235.4a0bX7vO2r Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Hi David, On Friday 25 April 2014 09:44:17 David Daney wrote: > On 04/25/2014 08:19 AM, James Hogan wrote: > > Contrary to the comment, the guest CP0_EPC register cannot be set via > > kvm_regs, since it is distinct from the guest PC. Add the EPC register > > to the KVM_{GET,SET}_ONE_REG ioctl interface. > > > > Signed-off-by: James Hogan > > Cc: Paolo Bonzini > > Cc: Gleb Natapov > > Cc: kvm@vger.kernel.org > > Cc: Ralf Baechle > > Cc: linux-mips@linux-mips.org > > Cc: David Daney > > Cc: Sanjay Lal > > NACK... > > > --- > > > > arch/mips/kvm/kvm_mips.c | 9 ++++++++- > > 1 file changed, 8 insertions(+), 1 deletion(-) > > > > diff --git a/arch/mips/kvm/kvm_mips.c b/arch/mips/kvm/kvm_mips.c > > index 46cea0bad518..db41876cbac5 100644 > > --- a/arch/mips/kvm/kvm_mips.c > > +++ b/arch/mips/kvm/kvm_mips.c > > @@ -512,6 +512,7 @@ kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu, > > > > #define KVM_REG_MIPS_CP0_COMPARE MIPS_CP0_32(11, 0) > > #define KVM_REG_MIPS_CP0_STATUS MIPS_CP0_32(12, 0) > > #define KVM_REG_MIPS_CP0_CAUSE MIPS_CP0_32(13, 0) > > > > +#define KVM_REG_MIPS_CP0_EPC MIPS_CP0_64(14, 0) > > This is already called KVM_REG_MIPS_PC, you cannot change that. KVM_REG_MIPS_PC gets you vcpu->arch.pc, i.e. the next address of guest execution. KVM_REG_MIPS_CP0_EPC gets you the guest's CP0 EPC register which is the PC of the last guest exception. They are quite distinct state, even though vcpu->arch.pc is read from the *root context*'s CP0 EPC register after an exception or interrupt. Cheers James > > > #define KVM_REG_MIPS_CP0_EBASE MIPS_CP0_32(15, 1) > > #define KVM_REG_MIPS_CP0_CONFIG MIPS_CP0_32(16, 0) > > #define KVM_REG_MIPS_CP0_CONFIG1 MIPS_CP0_32(16, 1) > > > > @@ -567,7 +568,7 @@ static u64 kvm_mips_get_one_regs[] = { > > > > KVM_REG_MIPS_CP0_ENTRYHI, > > KVM_REG_MIPS_CP0_STATUS, > > KVM_REG_MIPS_CP0_CAUSE, > > > > - /* EPC set via kvm_regs, et al. */ > > + KVM_REG_MIPS_CP0_EPC, > > > > KVM_REG_MIPS_CP0_CONFIG, > > KVM_REG_MIPS_CP0_CONFIG1, > > KVM_REG_MIPS_CP0_CONFIG2, > > > > @@ -620,6 +621,9 @@ static int kvm_mips_get_reg(struct kvm_vcpu *vcpu, > > > > case KVM_REG_MIPS_CP0_CAUSE: > > v = (long)kvm_read_c0_guest_cause(cop0); > > break; > > > > + case KVM_REG_MIPS_CP0_EPC: > > + v = (long)kvm_read_c0_guest_epc(cop0); > > + break; > > > > case KVM_REG_MIPS_CP0_ERROREPC: > > v = (long)kvm_read_c0_guest_errorepc(cop0); > > break; > > > > @@ -716,6 +720,9 @@ static int kvm_mips_set_reg(struct kvm_vcpu *vcpu, > > > > case KVM_REG_MIPS_CP0_CAUSE: > > kvm_write_c0_guest_cause(cop0, v); > > break; > > > > + case KVM_REG_MIPS_CP0_EPC: > > + kvm_write_c0_guest_epc(cop0, v); > > + break; > > > > case KVM_REG_MIPS_CP0_ERROREPC: > > kvm_write_c0_guest_errorepc(cop0, v); > > break; --nextPart2325235.4a0bX7vO2r Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part. Content-Transfer-Encoding: 7Bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iQIcBAABAgAGBQJTWsWlAAoJEKHZs+irPybflzAP/iCr+/XRp8IfyYH8TTTtVluf oAJ2qMZGqC+Jt9uA6+2T6PkaUiwuO115EtawbHmx9iWU2OnJECrGftw7lQn3PmqG pNJErGWzrp3wEKMxKb9vDPjuXdN2eNm0LGG9STyZ3QP/x3eNH7OnnI5WKhTDbtoZ hgWpLbrm+ArnEtaxV3WTKlYlOYp/9tLhG1Jd29/xR0CXsDhYs0bOCTW7SpJ7JiWg Qf7J8Cls4DVv76sZZ8BCUsjLFWq9p+nEhRME08QAVpkXnvbeaRzuhLSkI9UhitC7 v2sxM25aN/vCN5QRwAdj5n5IEOl2fJo8/sztVICh1K3uwkPl2ik4r9z/eFOg+a1t mFGt8PNa9crJ7L8zwNMysWRmY7beePwtoT1mbM14rZAMU/dIM5az64GPXYT3Kdjp o/+CEeTHn7eQgqXGMxJh+bINUR4hfSXjnpPFdvC3BR13FogT9vt/cd0j4oxTahKf EjJbROs4klXy7xBOvouEKd1jg9aoa1Sv+Tnd1HHT3GpS8AEpmvcFrQe0atFgz1X8 9GSVbBVJJNwZZjtX2jk6uIuP2CIUOCqbA4akQIhAbrKsHCyA2uGYiDJYicYJ4Hcr hwHD2qwH4+3BfgIVVfkGPNzKxZ7RMwqUa6NsAD5JXyYFjaODr7CSYmKRvSlNlzcw 3UC9di2dgStPDjKM7qZm =o2wg -----END PGP SIGNATURE----- --nextPart2325235.4a0bX7vO2r--