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KVM: MIPS/VZ: VZ hardware setup for Octeon III

Browse source 
Set up hardware virtualisation on Octeon III cores, configuring guest
interrupt routing and carving out half of the root TLB for guest use,
restoring it back again afterwards.

We need to be careful to inhibit TLB shutdown machine check exceptions
while invalidating guest TLB entries, since TLB invalidation is not
available so guest entries must be invalidated by setting them to unique
unmapped addresses, which could conflict with mappings set by the guest
or root if recently repartitioned.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: David Daney <david.daney@cavium.com>
Cc: Andreas Herrmann <andreas.herrmann@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
This commit is contained in:
James Hogan 2017-03-14 10:25:48 +00:00
parent 867f4da752
commit 824533ad16
2 changed files with 107 additions and 27 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

16
arch/mips/kvm/tlb.c
View file

@ -447,6 +447,7 @@ void kvm_vz_local_flush_guesttlb_all(void)
unsigned long old_entrylo[2];
unsigned long old_pagemask;
int entry;
u64 cvmmemctl2 = 0;
local_irq_save(flags);
@ -457,6 +458,15 @@ void kvm_vz_local_flush_guesttlb_all(void)
old_entrylo[1] = read_gc0_entrylo1();
old_pagemask = read_gc0_pagemask();
switch (current_cpu_type()) {
case CPU_CAVIUM_OCTEON3:
/* Inhibit machine check due to multiple matching TLB entries */
cvmmemctl2 = read_c0_cvmmemctl2();
cvmmemctl2 |= CVMMEMCTL2_INHIBITTS;
write_c0_cvmmemctl2(cvmmemctl2);
break;
};
/* Invalidate guest entries in guest TLB */
write_gc0_entrylo0(0);
write_gc0_entrylo1(0);
@ -468,6 +478,12 @@ void kvm_vz_local_flush_guesttlb_all(void)
mtc0_tlbw_hazard();
guest_tlb_write_indexed();
}
if (cvmmemctl2) {
cvmmemctl2 &= ~CVMMEMCTL2_INHIBITTS;
write_c0_cvmmemctl2(cvmmemctl2);
};
write_gc0_index(old_index);
write_gc0_entryhi(old_entryhi);
write_gc0_entrylo0(old_entrylo[0]);

118
arch/mips/kvm/vz.c
View file

@ -2747,37 +2747,73 @@ static unsigned int kvm_vz_resize_guest_vtlb(unsigned int size)
static int kvm_vz_hardware_enable(void)
{
unsigned int mmu_size, guest_mmu_size, ftlb_size;
u64 guest_cvmctl, cvmvmconfig;
/*
* ImgTec cores tend to use a shared root/guest TLB. To avoid overlap of
* root wired and guest entries, the guest TLB may need resizing.
*/
mmu_size = current_cpu_data.tlbsizevtlb;
ftlb_size = current_cpu_data.tlbsize - mmu_size;
switch (current_cpu_type()) {
case CPU_CAVIUM_OCTEON3:
/* Set up guest timer/perfcount IRQ lines */
guest_cvmctl = read_gc0_cvmctl();
guest_cvmctl &= ~CVMCTL_IPTI;
guest_cvmctl |= 7ull << CVMCTL_IPTI_SHIFT;
guest_cvmctl &= ~CVMCTL_IPPCI;
guest_cvmctl |= 6ull << CVMCTL_IPPCI_SHIFT;
write_gc0_cvmctl(guest_cvmctl);
/* Try switching to maximum guest VTLB size for flush */
guest_mmu_size = kvm_vz_resize_guest_vtlb(mmu_size);
current_cpu_data.guest.tlbsize = guest_mmu_size + ftlb_size;
kvm_vz_local_flush_guesttlb_all();
cvmvmconfig = read_c0_cvmvmconfig();
/* No I/O hole translation. */
cvmvmconfig |= CVMVMCONF_DGHT;
/* Halve the root MMU size */
mmu_size = ((cvmvmconfig & CVMVMCONF_MMUSIZEM1)
>> CVMVMCONF_MMUSIZEM1_S) + 1;
guest_mmu_size = mmu_size / 2;
mmu_size -= guest_mmu_size;
cvmvmconfig &= ~CVMVMCONF_RMMUSIZEM1;
cvmvmconfig |= mmu_size - 1;
write_c0_cvmvmconfig(cvmvmconfig);
/*
* Reduce to make space for root wired entries and at least 2 root
* non-wired entries. This does assume that long-term wired entries
* won't be added later.
*/
guest_mmu_size = mmu_size - num_wired_entries() - 2;
guest_mmu_size = kvm_vz_resize_guest_vtlb(guest_mmu_size);
current_cpu_data.guest.tlbsize = guest_mmu_size + ftlb_size;
/* Update our records */
current_cpu_data.tlbsize = mmu_size;
current_cpu_data.tlbsizevtlb = mmu_size;
current_cpu_data.guest.tlbsize = guest_mmu_size;
/*
* Write the VTLB size, but if another CPU has already written, check it
* matches or we won't provide a consistent view to the guest. If this
* ever happens it suggests an asymmetric number of wired entries.
*/
if (cmpxchg(&kvm_vz_guest_vtlb_size, 0, guest_mmu_size) &&
WARN(guest_mmu_size != kvm_vz_guest_vtlb_size,
"Available guest VTLB size mismatch"))
return -EINVAL;
/* Flush moved entries in new (guest) context */
kvm_vz_local_flush_guesttlb_all();
break;
default:
/*
* ImgTec cores tend to use a shared root/guest TLB. To avoid
* overlap of root wired and guest entries, the guest TLB may
* need resizing.
*/
mmu_size = current_cpu_data.tlbsizevtlb;
ftlb_size = current_cpu_data.tlbsize - mmu_size;
/* Try switching to maximum guest VTLB size for flush */
guest_mmu_size = kvm_vz_resize_guest_vtlb(mmu_size);
current_cpu_data.guest.tlbsize = guest_mmu_size + ftlb_size;
kvm_vz_local_flush_guesttlb_all();
/*
* Reduce to make space for root wired entries and at least 2
* root non-wired entries. This does assume that long-term wired
* entries won't be added later.
*/
guest_mmu_size = mmu_size - num_wired_entries() - 2;
guest_mmu_size = kvm_vz_resize_guest_vtlb(guest_mmu_size);
current_cpu_data.guest.tlbsize = guest_mmu_size + ftlb_size;
/*
* Write the VTLB size, but if another CPU has already written,
* check it matches or we won't provide a consistent view to the
* guest. If this ever happens it suggests an asymmetric number
* of wired entries.
*/
if (cmpxchg(&kvm_vz_guest_vtlb_size, 0, guest_mmu_size) &&
WARN(guest_mmu_size != kvm_vz_guest_vtlb_size,
"Available guest VTLB size mismatch"))
return -EINVAL;
break;
}
/*
* Enable virtualization features granting guest direct control of
@ -2814,8 +2850,36 @@ static int kvm_vz_hardware_enable(void)
static void kvm_vz_hardware_disable(void)
{
u64 cvmvmconfig;
unsigned int mmu_size;
/* Flush any remaining guest TLB entries */
kvm_vz_local_flush_guesttlb_all();
switch (current_cpu_type()) {
case CPU_CAVIUM_OCTEON3:
/*
* Allocate whole TLB for root. Existing guest TLB entries will
* change ownership to the root TLB. We should be safe though as
* they've already been flushed above while in guest TLB.
*/
cvmvmconfig = read_c0_cvmvmconfig();
mmu_size = ((cvmvmconfig & CVMVMCONF_MMUSIZEM1)
>> CVMVMCONF_MMUSIZEM1_S) + 1;
cvmvmconfig &= ~CVMVMCONF_RMMUSIZEM1;
cvmvmconfig |= mmu_size - 1;
write_c0_cvmvmconfig(cvmvmconfig);
/* Update our records */
current_cpu_data.tlbsize = mmu_size;
current_cpu_data.tlbsizevtlb = mmu_size;
current_cpu_data.guest.tlbsize = 0;
/* Flush moved entries in new (root) context */
local_flush_tlb_all();
break;
}
if (cpu_has_guestid) {
write_c0_guestctl1(0);
kvm_vz_local_flush_roottlb_all_guests();