diff options
| author | Claudio Imbrenda <imbrenda@linux.ibm.com> | 2021-09-20 16:24:54 +0300 |
|---|---|---|
| committer | Christian Borntraeger <borntraeger@de.ibm.com> | 2021-10-27 08:55:53 +0300 |
| commit | 380d97bd02fca7b9b41aec2d1c767874d602bc78 (patch) | |
| tree | 8e9f822ec608744ebcb9f4e5ddb293936e59393a /arch/s390/kernel/uv.c | |
| parent | 85f517b29418158d3e6e90c3f0fc01b306d2f1a1 (diff) | |
| download | linux-380d97bd02fca7b9b41aec2d1c767874d602bc78.tar.xz | |
KVM: s390: pv: properly handle page flags for protected guests
Introduce variants of the convert and destroy page functions that also
clear the PG_arch_1 bit used to mark them as secure pages.
The PG_arch_1 flag is always allowed to overindicate; using the new
functions introduced here allows to reduce the extent of overindication
and thus improve performance.
These new functions can only be called on pages for which a reference
is already being held.
Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Link: https://lore.kernel.org/r/20210920132502.36111-7-imbrenda@linux.ibm.com
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Diffstat (limited to 'arch/s390/kernel/uv.c')
| -rw-r--r-- | arch/s390/kernel/uv.c | 34 |
1 files changed, 33 insertions, 1 deletions
diff --git a/arch/s390/kernel/uv.c b/arch/s390/kernel/uv.c index 09b80d371409..8b0e62507d62 100644 --- a/arch/s390/kernel/uv.c +++ b/arch/s390/kernel/uv.c @@ -100,7 +100,7 @@ static int uv_pin_shared(unsigned long paddr) * * @paddr: Absolute host address of page to be destroyed */ -int uv_destroy_page(unsigned long paddr) +static int uv_destroy_page(unsigned long paddr) { struct uv_cb_cfs uvcb = { .header.cmd = UVC_CMD_DESTR_SEC_STOR, @@ -121,6 +121,22 @@ int uv_destroy_page(unsigned long paddr) } /* + * The caller must already hold a reference to the page + */ +int uv_destroy_owned_page(unsigned long paddr) +{ + struct page *page = phys_to_page(paddr); + int rc; + + get_page(page); + rc = uv_destroy_page(paddr); + if (!rc) + clear_bit(PG_arch_1, &page->flags); + put_page(page); + return rc; +} + +/* * Requests the Ultravisor to encrypt a guest page and make it * accessible to the host for paging (export). * @@ -140,6 +156,22 @@ int uv_convert_from_secure(unsigned long paddr) } /* + * The caller must already hold a reference to the page + */ +int uv_convert_owned_from_secure(unsigned long paddr) +{ + struct page *page = phys_to_page(paddr); + int rc; + + get_page(page); + rc = uv_convert_from_secure(paddr); + if (!rc) + clear_bit(PG_arch_1, &page->flags); + put_page(page); + return rc; +} + +/* * Calculate the expected ref_count for a page that would otherwise have no * further pins. This was cribbed from similar functions in other places in * the kernel, but with some slight modifications. We know that a secure |