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| author | Tom Lendacky <thomas.lendacky@amd.com> | 2023-06-06 09:51:25 -0500 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2023-06-06 18:29:35 +0200 |
| commit | 15d9088779b8693cffe47527ea4f9ff8fde4cd03 (patch) | |
| tree | 271d77c3f7cba731662b8b11db4ac05ff4d9e203 /arch/x86/include/asm/sev.h | |
| parent | 7006b75592feb1902563ac1decfd98d7e4a0dd6c (diff) | |
| download | lwn-15d9088779b8693cffe47527ea4f9ff8fde4cd03.tar.gz lwn-15d9088779b8693cffe47527ea4f9ff8fde4cd03.zip | |
x86/sev: Use large PSC requests if applicable
In advance of providing support for unaccepted memory, request 2M Page
State Change (PSC) requests when the address range allows for it. By using
a 2M page size, more PSC operations can be handled in a single request to
the hypervisor. The hypervisor will determine if it can accommodate the
larger request by checking the mapping in the nested page table. If mapped
as a large page, then the 2M page request can be performed, otherwise the
2M page request will be broken down into 512 4K page requests. This is
still more efficient than having the guest perform multiple PSC requests
in order to process the 512 4K pages.
In conjunction with the 2M PSC requests, attempt to perform the associated
PVALIDATE instruction of the page using the 2M page size. If PVALIDATE
fails with a size mismatch, then fallback to validating 512 4K pages. To
do this, page validation is modified to work with the PSC structure and
not just a virtual address range.
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/050d17b460dfc237b51d72082e5df4498d3513cb.1686063086.git.thomas.lendacky@amd.com
Diffstat (limited to 'arch/x86/include/asm/sev.h')
| -rw-r--r-- | arch/x86/include/asm/sev.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/include/asm/sev.h b/arch/x86/include/asm/sev.h index 7ca5c9ec8b52..e21e1c5397c1 100644 --- a/arch/x86/include/asm/sev.h +++ b/arch/x86/include/asm/sev.h @@ -80,11 +80,15 @@ extern void vc_no_ghcb(void); extern void vc_boot_ghcb(void); extern bool handle_vc_boot_ghcb(struct pt_regs *regs); +/* PVALIDATE return codes */ +#define PVALIDATE_FAIL_SIZEMISMATCH 6 + /* Software defined (when rFlags.CF = 1) */ #define PVALIDATE_FAIL_NOUPDATE 255 /* RMP page size */ #define RMP_PG_SIZE_4K 0 +#define RMP_PG_SIZE_2M 1 #define RMPADJUST_VMSA_PAGE_BIT BIT(16) |