ARM: KVM: add world-switch for AMAIR{0,1}

HCR.TVM traps (among other things) accesses to AMAIR0 and AMAIR1.
In order to minimise the amount of surprise a guest could generate by
trying to access these registers with caches off, add them to the
list of registers we switch/handle.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h
index 661da11..53b3c4a 100644 (file)
--- a/arch/arm/include/asm/kvm_asm.h
+++ b/arch/arm/include/asm/kvm_asm.h
@@ -48,7 +48,9 @@
 #define c13_TID_URO    26      /* Thread ID, User R/O */
 #define c13_TID_PRIV   27      /* Thread ID, Privileged */
 #define c14_CNTKCTL    28      /* Timer Control Register (PL1) */
-#define NR_CP15_REGS   29      /* Number of regs (incl. invalid) */
+#define c10_AMAIR0     29      /* Auxilary Memory Attribute Indirection Reg0 */
+#define c10_AMAIR1     30      /* Auxilary Memory Attribute Indirection Reg1 */
+#define NR_CP15_REGS   31      /* Number of regs (incl. invalid) */
 
 #define ARM_EXCEPTION_RESET      0
 #define ARM_EXCEPTION_UNDEFINED   1

diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c
index 126c90d..a5a54a4 100644 (file)
--- a/arch/arm/kvm/coproc.c
+++ b/arch/arm/kvm/coproc.c
@@ -328,6 +328,12 @@ static const struct coproc_reg cp15_regs[] = {
        { CRn(10), CRm( 2), Op1( 0), Op2( 1), is32,
                        NULL, reset_unknown, c10_NMRR},
 
+       /* AMAIR0/AMAIR1: swapped by interrupt.S. */
+       { CRn(10), CRm( 3), Op1( 0), Op2( 0), is32,
+                       access_vm_reg, reset_unknown, c10_AMAIR0},
+       { CRn(10), CRm( 3), Op1( 0), Op2( 1), is32,
+                       access_vm_reg, reset_unknown, c10_AMAIR1},
+
        /* VBAR: swapped by interrupt.S. */
        { CRn(12), CRm( 0), Op1( 0), Op2( 0), is32,
                        NULL, reset_val, c12_VBAR, 0x00000000 },

diff --git a/arch/arm/kvm/interrupts_head.S b/arch/arm/kvm/interrupts_head.S
index a37270d..76af930 100644 (file)
--- a/arch/arm/kvm/interrupts_head.S
+++ b/arch/arm/kvm/interrupts_head.S
@@ -303,13 +303,17 @@ vcpu      .req    r0              @ vcpu pointer always in r0
 
        mrc     p15, 0, r2, c14, c1, 0  @ CNTKCTL
        mrrc    p15, 0, r4, r5, c7      @ PAR
+       mrc     p15, 0, r6, c10, c3, 0  @ AMAIR0
+       mrc     p15, 0, r7, c10, c3, 1  @ AMAIR1
 
        .if \store_to_vcpu == 0
-       push    {r2,r4-r5}
+       push    {r2,r4-r7}
        .else
        str     r2, [vcpu, #CP15_OFFSET(c14_CNTKCTL)]
        add     r12, vcpu, #CP15_OFFSET(c7_PAR)
        strd    r4, r5, [r12]
+       str     r6, [vcpu, #CP15_OFFSET(c10_AMAIR0)]
+       str     r7, [vcpu, #CP15_OFFSET(c10_AMAIR1)]
        .endif
 .endm
 
@@ -322,15 +326,19 @@ vcpu      .req    r0              @ vcpu pointer always in r0
  */
 .macro write_cp15_state read_from_vcpu
        .if \read_from_vcpu == 0
-       pop     {r2,r4-r5}
+       pop     {r2,r4-r7}
        .else
        ldr     r2, [vcpu, #CP15_OFFSET(c14_CNTKCTL)]
        add     r12, vcpu, #CP15_OFFSET(c7_PAR)
        ldrd    r4, r5, [r12]
+       ldr     r6, [vcpu, #CP15_OFFSET(c10_AMAIR0)]
+       ldr     r7, [vcpu, #CP15_OFFSET(c10_AMAIR1)]
        .endif
 
        mcr     p15, 0, r2, c14, c1, 0  @ CNTKCTL
        mcrr    p15, 0, r4, r5, c7      @ PAR
+       mcr     p15, 0, r6, c10, c3, 0  @ AMAIR0
+       mcr     p15, 0, r7, c10, c3, 1  @ AMAIR1
 
        .if \read_from_vcpu == 0
        pop     {r2-r12}