Some special-purpose registers that were present and accessible by guests on POWER8 no longer exist on POWER9, so this adds feature sections to ensure that we don't try to context-switch them when going into or out of a guest on POWER9. These are all relatively obscure, rarely-used registers, but we had to context-switch them on POWER8 to avoid creating a covert channel. They are: SPMC1, SPMC2, MMCRS, CSIGR, TACR, TCSCR, and ACOP. Signed-off-by: Paul Mackerras <paulus@xxxxxxxxxx> --- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 50 ++++++++++++++++++++------------- 1 file changed, 30 insertions(+), 20 deletions(-) diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index dc25467..d422014 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -752,14 +752,16 @@ END_FTR_SECTION_IFSET(CPU_FTR_PMAO_BUG) BEGIN_FTR_SECTION ld r5, VCPU_MMCR + 24(r4) ld r6, VCPU_SIER(r4) + mtspr SPRN_MMCR2, r5 + mtspr SPRN_SIER, r6 +BEGIN_FTR_SECTION_NESTED(96) lwz r7, VCPU_PMC + 24(r4) lwz r8, VCPU_PMC + 28(r4) ld r9, VCPU_MMCR + 32(r4) - mtspr SPRN_MMCR2, r5 - mtspr SPRN_SIER, r6 mtspr SPRN_SPMC1, r7 mtspr SPRN_SPMC2, r8 mtspr SPRN_MMCRS, r9 +END_FTR_SECTION_NESTED(CPU_FTR_ARCH_300, 0, 96) END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) mtspr SPRN_MMCR0, r3 isync @@ -815,20 +817,22 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S) mtspr SPRN_EBBHR, r8 ld r5, VCPU_EBBRR(r4) ld r6, VCPU_BESCR(r4) - ld r7, VCPU_CSIGR(r4) - ld r8, VCPU_TACR(r4) + lwz r7, VCPU_GUEST_PID(r4) + ld r8, VCPU_WORT(r4) mtspr SPRN_EBBRR, r5 mtspr SPRN_BESCR, r6 - mtspr SPRN_CSIGR, r7 - mtspr SPRN_TACR, r8 + mtspr SPRN_PID, r7 + mtspr SPRN_WORT, r8 +BEGIN_FTR_SECTION ld r5, VCPU_TCSCR(r4) ld r6, VCPU_ACOP(r4) - lwz r7, VCPU_GUEST_PID(r4) - ld r8, VCPU_WORT(r4) + ld r7, VCPU_CSIGR(r4) + ld r8, VCPU_TACR(r4) mtspr SPRN_TCSCR, r5 mtspr SPRN_ACOP, r6 - mtspr SPRN_PID, r7 - mtspr SPRN_WORT, r8 + mtspr SPRN_CSIGR, r7 + mtspr SPRN_TACR, r8 +END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300) 8: /* @@ -1343,20 +1347,22 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S) std r8, VCPU_EBBHR(r9) mfspr r5, SPRN_EBBRR mfspr r6, SPRN_BESCR - mfspr r7, SPRN_CSIGR - mfspr r8, SPRN_TACR + mfspr r7, SPRN_PID + mfspr r8, SPRN_WORT std r5, VCPU_EBBRR(r9) std r6, VCPU_BESCR(r9) - std r7, VCPU_CSIGR(r9) - std r8, VCPU_TACR(r9) + stw r7, VCPU_GUEST_PID(r9) + std r8, VCPU_WORT(r9) +BEGIN_FTR_SECTION mfspr r5, SPRN_TCSCR mfspr r6, SPRN_ACOP - mfspr r7, SPRN_PID - mfspr r8, SPRN_WORT + mfspr r7, SPRN_CSIGR + mfspr r8, SPRN_TACR std r5, VCPU_TCSCR(r9) std r6, VCPU_ACOP(r9) - stw r7, VCPU_GUEST_PID(r9) - std r8, VCPU_WORT(r9) + std r7, VCPU_CSIGR(r9) + std r8, VCPU_TACR(r9) +END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300) /* * Restore various registers to 0, where non-zero values * set by the guest could disrupt the host. @@ -1365,12 +1371,14 @@ END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_207S) mtspr SPRN_IAMR, r0 mtspr SPRN_CIABR, r0 mtspr SPRN_DAWRX, r0 - mtspr SPRN_TCSCR, r0 mtspr SPRN_WORT, r0 +BEGIN_FTR_SECTION + mtspr SPRN_TCSCR, r0 /* Set MMCRS to 1<<31 to freeze and disable the SPMC counters */ li r0, 1 sldi r0, r0, 31 mtspr SPRN_MMCRS, r0 +END_FTR_SECTION_IFCLR(CPU_FTR_ARCH_300) 8: /* Save and reset AMR and UAMOR before turning on the MMU */ @@ -1504,15 +1512,17 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) stw r8, VCPU_PMC + 20(r9) BEGIN_FTR_SECTION mfspr r5, SPRN_SIER + std r5, VCPU_SIER(r9) +BEGIN_FTR_SECTION_NESTED(96) mfspr r6, SPRN_SPMC1 mfspr r7, SPRN_SPMC2 mfspr r8, SPRN_MMCRS - std r5, VCPU_SIER(r9) stw r6, VCPU_PMC + 24(r9) stw r7, VCPU_PMC + 28(r9) std r8, VCPU_MMCR + 32(r9) lis r4, 0x8000 mtspr SPRN_MMCRS, r4 +END_FTR_SECTION_NESTED(CPU_FTR_ARCH_300, 0, 96) END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) 22: /* Clear out SLB */ -- 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
