leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

powerpc/xive: Share the event-queue page with the Hypervisor.

Browse Source 
XIVE interrupt controller uses an Event Queue (EQ) to enqueue event
notifications when an exception occurs. The EQ is a single memory page
provided by the O/S defining a circular buffer, one per server and
priority couple.

On baremetal, the EQ page is configured with an OPAL call. On pseries,
an extra hop is necessary and the guest OS uses the hcall
H_INT_SET_QUEUE_CONFIG to configure the XIVE interrupt controller.

The XIVE controller being Hypervisor privileged, it will not be allowed
to enqueue event notifications for a Secure VM unless the EQ pages are
shared by the Secure VM.

Hypervisor/Ultravisor still requires support for the TIMA and ESB page
fault handlers. Until this is complete, QEMU can use the emulated XIVE
device for Secure VMs, option "kernel_irqchip=off" on the QEMU pseries
machine.

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Reviewed-by: Cedric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200426020518.GC5853@oc0525413822.ibm.com
This commit is contained in:
Ram Pai 2020-02-24 01:09:48 -05:00 committed by Michael Ellerman
parent 373b373053
commit 094235222d
1 changed files with 7 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
arch/powerpc/sysdev/xive/spapr.c
View File

@ -27,6 +27,8 @@
#include <asm/xive.h>
#include <asm/xive-regs.h>
#include <asm/hvcall.h>
#include <asm/svm.h>
#include <asm/ultravisor.h>
#include "xive-internal.h"
@ -502,6 +504,9 @@ static int xive_spapr_configure_queue(u32 target, struct xive_q *q, u8 prio,
rc = -EIO;
} else {
q->qpage = qpage;
if (is_secure_guest())
uv_share_page(PHYS_PFN(qpage_phys),
1 << xive_alloc_order(order));
}
fail:
return rc;
@ -535,6 +540,8 @@ static void xive_spapr_cleanup_queue(unsigned int cpu, struct xive_cpu *xc,
hw_cpu, prio);
alloc_order = xive_alloc_order(xive_queue_shift);
if (is_secure_guest())
uv_unshare_page(PHYS_PFN(__pa(q->qpage)), 1 << alloc_order);
free_pages((unsigned long)q->qpage, alloc_order);
q->qpage = NULL;
}